grep (used to ensure bundler availability) is not readily available on MS Windows

[mlt]

'grep' is not recognized as an internal or external command,
operable program or batch file.
>> Reinstall Bundler into C:/tools/Ruby24-x64/lib/ruby/gems/2.4.0
Successfully installed bundler-1.16.4
Parsing documentation for bundler-1.16.4
Done installing documentation for bundler after 7 seconds
1 gem installed

https://github.com/thoughtbot/appraisal/blob/5d1edf642091ca38f83cf2ae1cf9624fa23546c8/lib/appraisal/command.rb#L44

[nickcharlton]

I've not used Windows in many, many years, but I agree that this is something we should be better about.

Is there a solution to this which is similar in spirit but could be done easily enough?

Asking around, I had findstr suggested, which would mean we change that line to:

gem list -q "^bundler$" | findstr "bundler"

But this is not something I can test. What do you think?

[nickcharlton]

Perhaps a better solution is to just do this in Ruby:

`gem list -q '^bundler'`.split(/\n/).any?

[nickcharlton]

I'm going to close this as #168 removes that reference of grep, which is nice!