rake test broken, fix with Gemfile change

[mMerlin]

Doing a simple:

git clone https://github.com/zencoder/zencoder-rb.git
cd zencoder-rb
bundle install
rake test

failed all over the place. See below.

Doing a bunch of web searches and testing suggestions kept changing the messages, but did not fix it. Finally got to a one line fix. Add

  gem "minitest", "4.7.5"

to group :test in the Gemfile.

I do not know if there is a better solution, or will be when something else gets updated, but it appears that minitest 5 is not compatible with current versions of other things.

My environment:

$ ruby --version
ruby 2.1.5p273 (2014-11-13 revision 48405) [i386-linux]
$ rails --version
Rails 4.2.0
$ uname -a
Linux pajeros.felinae 3.18.7-200.fc21.i686 #1 SMP Wed Feb 11 22:26:31 UTC 2015 i686 i686 i386 GNU/Linux

$ rake test
/usr/bin/ruby -I"lib:lib:test" -I"/home/phil/.gem/ruby/gems/rake-10.4.2/lib" "/home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb" "test/**/*_test.rb" 
/usr/share/ruby/test/unit.rb:1:in `require': cannot load such file -- minitest/unit (LoadError)
    from /usr/share/ruby/test/unit.rb:1:in `<top (required)>'
    from /home/phil/.gem/ruby/gems/shoulda-2.11.3/lib/shoulda/integrations/test_unit.rb:1:in `require'
    from /home/phil/.gem/ruby/gems/shoulda-2.11.3/lib/shoulda/integrations/test_unit.rb:1:in `<top (required)>'
    from /home/phil/.gem/ruby/gems/shoulda-2.11.3/lib/shoulda.rb:8:in `require'
    from /home/phil/.gem/ruby/gems/shoulda-2.11.3/lib/shoulda.rb:8:in `<top (required)>'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler/runtime.rb:76:in `require'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler/runtime.rb:76:in `block (2 levels) in require'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler/runtime.rb:72:in `each'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler/runtime.rb:72:in `block in require'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler/runtime.rb:61:in `each'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler/runtime.rb:61:in `require'
    from /usr/share/gems/gems/bundler-1.7.6/lib/bundler.rb:133:in `require'
    from /home/phil/development/dissolve/zencoder-rb/test/test_helper.rb:4:in `<top (required)>'
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/phil/development/dissolve/zencoder-rb/test/zencoder/account_test.rb:1:in `<top (required)>'
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/share/rubygems/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb:10:in `block (2 levels) in <main>'
    from /home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb:9:in `each'
    from /home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb:9:in `block in <main>'
    from /home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb:4:in `select'
    from /home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb:4:in `<main>'
rake aborted!
Command failed with status (1): [ruby -I"lib:lib:test" -I"/home/phil/.gem/ruby/gems/rake-10.4.2/lib" "/home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb" "test/**/*_test.rb" ]

Tasks: TOP => test
(See full trace by running task with --trace)

After the Gemfile change, and bundle install:

$ rake test
/usr/bin/ruby -I"lib:lib:test" -I"/home/phil/.gem/ruby/gems/rake-10.4.2/lib" "/home/phil/.gem/ruby/gems/rake-10.4.2/lib/rake/rake_test_loader.rb" "test/**/*_test.rb" 
Run options: 

# Running tests:

[ 1/79] Zencoder::AccountTest#test: Zencoder::Account .create should POS[WARNING] MultiJson is using the default adapter (ok_json).We recommend loading a different JSON library to improve performance.
Finished tests in 0.493223s, 160.1710 tests/s, 253.4351 assertions/s.           
79 tests, 125 assertions, 0 failures, 0 errors, 0 skips

ruby -v: ruby 2.1.5p273 (2014-11-13 revision 48405) [i386-linux]