Compatible with RubyMotion 3.6?

I am trying to use motion-screenshots but can't seem to get it to work. When I run rake screenshots, no screenshots are created and the app blows up when I ctrl-c the terminal window running the simulator. As the setup seems dead simple, I'm a little confused as to what's wrong. I've included the shell output at the bottom of this (long) issue.

I've created a simple repository illustrating the behavior: https://github.com/mwise/motion-screenshots-test

A few things I've noticed:

I've got no other CocoaPods installed in this contrived app - I'm not sure if that is causing the exit to blow up when it tries to reinstall my pods that don't exist. Seems like that might be the issue.
The check for KSScreenshotManager is failing on https://github.com/clayallsopp/motion-screenshots/blob/master/lib/motion/motion-screenshots.rb#L1 when I run rake screenshots. So I think that explains the screenshots not being taken but also not blowing up. It seems like maybe the `pod 'KSScreenshotManager' at https://github.com/clayallsopp/motion-screenshots/blob/master/lib/motion-screenshots.rb#L39 isn't being respected or something.
If I manually add the KSScreenshotManager pod via my app's rakefile, I get one of those beloved RubyMotion 'not precompiled' errors at runtime (not on exit as described above):

Objective-C stub for message `actionWithName:asynchronous:actionBlock:cleanupBlock:' type `@@:@c@?@?' not precompiled. Make sure you properly link with the framework or library that defines this message.

If rake screenshots blows up on exit, the next rake (not rake screenshots) will blow up, complaining about architecture flags or something:

→ rake
     Build ./build/iPhoneSimulator-8.1-Development
   Compile /tmp/motion_env_1425783585.rb
      Link ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app/motion-screenshots-test
ld: warning: ignoring file ./build/iPhoneSimulator-8.1-Development/objs/Users/mark/projects/ios/rubymotion/motion-screenshots-test/app/app_screenshots.rb.o, missing required architecture x86_64 in file ./build/iPhoneSimulator-8.1-Development/objs/Users/mark/projects/ios/
rubymotion/motion-screenshots-test/app/app_screenshots.rb.o (1 slices)
ld: warning: ignoring file ./build/iPhoneSimulator-8.1-Development/objs/Users/mark/projects/ios/rubymotion/motion-screenshots-test/app/my_first_view_controller.rb.o, missing required architecture x86_64 in file ./build/iPhoneSimulator-8.1-Development/objs/Users/mark/proj
ects/ios/rubymotion/motion-screenshots-test/app/my_first_view_controller.rb.o (1 slices)
Undefined symbols for architecture x86_64:
  "_MREP_319D6104414D487E945E0E0B9AA9A244", referenced from:
      _RubyMotionInit in init.o
  "_MREP_ABC42A576F184A6D9461F7E47F55A08F", referenced from:
      _RubyMotionInit in init.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
rake aborted!
Command failed with status (1): [/Applications/Xcode.app/Contents/Developer...]
/Library/RubyMotion/lib/motion/project/builder.rb:322:in `build'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-env-0.0.4/lib/motion-env/builder.rb:32:in `build_with_env'
/Library/RubyMotion/lib/motion/project/app.rb:78:in `build'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:53:in `build_with_cocoapods'
/Library/RubyMotion/lib/motion/project/template/ios.rb:68:in `block (2 levels) in <top (required)>'
/Library/RubyMotion/lib/motion/project/template/ios.rb:189:in `block in <top (required)>'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks:15:in `eval'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => build:simulator
(See full trace by running task with --trace)

So yeah, I'm not really sure what's going on. Have you noticed anything like the what I've described? It seems like there might be a few different issues at play, but I tried to craft the "Hello World" of motion-screenshot implementations. I'm running RubyMotion 3.6, Ruby 2.1.2 on OS X. I'd be happy to try to PR a fix or two if you can point me in the right direction.

Shell output from borked rake screenshots run:

 rake screenshots
  WARNING! Forcing 32bit-only build target for screenshots..
Updating spec repo `master`
Already up-to-date.

CocoaPods 0.36.0.rc.1 is available.
To update use: `sudo gem install cocoapods --pre`
[!] This is a test version we'd love you to try.

For more information see http://blog.cocoapods.org
and the CHANGELOG for this version http://git.io/BaH8pQ.

Analyzing dependencies
Downloading dependencies
Installing KSScreenshotManager (0.0.1)
Generating Pods project
     Build ./build/iPhoneSimulator-8.1-Development
   Compile /Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-screenshots-0.1.1/lib/motion/motion-screenshots.rb
   Compile ./app/my_first_view_controller.rb
   Compile ./app/app_screenshots.rb
   Compile ./app/app_delegate.rb
   Compile /tmp/motion_env_1425783989.rb
    Create ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app
      Link ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app/motion-screenshots-test
    Create ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app/PkgInfo
    Create ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app/Info.plist
      Copy ./resources/Default-568h@2x.png
      Copy ./resources/Default-667h@2x.png
      Copy ./resources/Default-736h@3x.png
    Create ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app.dSYM
  Simulate ./build/iPhoneSimulator-8.1-Development/motion-screenshots-test.app
(main)> rake aborted!
Interrupt: 
/Library/RubyMotion/lib/motion/project/template/ios.rb:235:in `system'
/Library/RubyMotion/lib/motion/project/template/ios.rb:235:in `block in <top (required)>'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-screenshots-0.1.1/lib/motion-screenshots.rb:96:in `block (2 levels) in <top (required)>'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks:15:in `eval'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => default => simulator
(See full trace by running task with --trace)
Re-installing pods...
rake aborted!
Errno::ENOENT: No such file or directory @ rb_sysopen - vendor/Pods/Target Support Files/Pods/Pods-resources.sh
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:305:in `initialize'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:305:in `open'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:305:in `resources'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:238:in `install_resources'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:230:in `install!'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/gems/motion-cocoapods-1.7.0/lib/motion/project/cocoapods.rb:348:in `block (2 levels) in <top (required)>'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks:15:in `eval'
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => pod:install
(See full trace by running task with --trace)
/Users/mark/.rvm/gems/ruby-2.1.2@motion-screenshots-test/bin/ruby_executable_hooks: Interrupt

clayallsopp / motion-screenshots

Compatible with RubyMotion 3.6? #7