Travis: Choose Trusty to build, have language Ruby

[olleolleolle]

This WIP PR tries to update the builds so that they run on the supported platforms.

• Travis: Change to target an explicit version of JRuby 1.7 (the Ruby 1.9 series) - the previous expression made rvm target 9.0.5.0
• Rake must be an earlier version to use the RSpec version in use
• add JRUBY_OPTS=--debug

Issues we ran into:

• NullPointerExceptions on finding backtrace lines (comes from elsewhere)
• Backtrace line-finding on JRuby 9.1.8.0 turns into a Bundler "friendly error" which is presented to the user without much information (Bundler error presentation)

Observations:

• RSpec is quite old, perhaps a newer version is good for the project

[kares]

thanks, unfortunately the specs do not boot - could you maybe try resolving the rspec compatibility issues?

[olleolleolle]

@kares (Will jruby-18mode remain a requirement?)

[kares]

@olleolleolle do not see why the requirements should change due travis-ci ... only if there was more work

also please keep the new failures at minimum :)

[!] There was an error parsing `Gemfile`: There are multiple gemspecs at /home/travis/build/cowboyd/therubyrhino. Please use the :name option to specify which one should be used. Bundler cannot continue.

 #  from /home/travis/build/cowboyd/therubyrhino/Gemfile:3
 #  -------------------------------------------
 #  
 >  gemspec
 #  
 #  -------------------------------------------

[olleolleolle]

@kares This is me trying to get the gemspec :name => 'therubyrhino' invocation to work. Update: This was just me being confused.

[olleolleolle]

This was the error that jruby-9.1.8.0 reported.

[!] There was an error parsing `Gemfile`: 
[!] There was an error while loading `therubyrhino.gemspec`: . Bundler cannot continue.
. Bundler cannot continue.
 #  from /home/travis/build/cowboyd/therubyrhino/Gemfile:3
 #  -------------------------------------------
 #  
 >  gemspec :name => "therubyrhino"
 #  
 #  -------------------------------------------

[olleolleolle]

(9.1.7.0 can run bundle exec rake on my OS X machine.)

[olleolleolle]

There's code where Bundler tries to parse out useful descriptive lines from the backtrace.

https://github.com/bundler/bundler/blob/9f414c55be8b749f46a0470277f14572c5246c03/lib/bundler/dsl.rb#L515

https://github.com/bundler/bundler/blob/9f414c55be8b749f46a0470277f14572c5246c03/lib/bundler/dsl.rb#L543-L551

This may fail on JRuby 9.1.8.0 with a ~dramatic bang~ whimper - where Bundler is unable to find anything that relates to the package at hand in the backtrace.

[kares]

I think the NPE has been introduced along the way with a commit (maybe a rhino.jar upgrade). code has been always a little edgy on cases, but those features are very unlikely to be used at all. I'm fine to merge this as is since it now at least runs the specs on CI.

[olleolleolle]

@kares Squashed change to a single commit.

[kares]

@olleolleolle Thanks!