Truncating resources-to-copy.txt if it already exists

Related #1080

This test was using Rake::FileList

Closes #1080

Englisherizer - fix a single case of imperfect english

* 'master' of https://github.com/CocoaPods/CocoaPods: (21 commits)
  Release 0.20.2
  [Sandbox] Allow sandbox-pod to execute any tool inside a rbenv prefix.
  Bump to 0.20.2
  [CHANGELOG] Cleanup.
  [Spec] Update integrations specs for 0.20.2
  [CHANGELOG] Update for 0.20.2
  [Sandbox] Allow any tool inside the Xcode.app bundle to be executed.
  [Sandbox] Ensure RubyGems loads the CP gem on system Ruby.
  Revert Changelog curated-created thing
  CHANGELOG typo
  Release 0.20.1
  Update integration specs for new version number.
  [CHANGELOG] Update for 0.20.1
  [Sandbox] Fix issues when installed as a gem.
  [Gemspec] Make sandbox-pod executable visible
  [Config] Fix space before parentheses
  [Gemspec] Require CLAide 0.3.1
  Release 0.20.0
  Prepare for 0.20.0 release
  [Config] Use the pwd as installation root if no Podfile can be found
  ...

Previous version didn't include all the files in lib

Closes #1046
Closes #1039