Removing pubspec.lock and adjusting .gitignore

[chalin]

Dart What Not to Commit recommends that pubspec.lock not be committed. I figured that having committed it might have contributed to the issue I reported yesterday (#10).

[chalin]

Hmm, quoting Dart What Not to Commit again: "For application packages, do commit pubspec.lock. This file is the recommended way for non-shared resources such as applications to manage their dependencies." I guess that angulardart-sample-app is an "application package"? If so you can ignore this PR, and apologies for the noise (I'm still learning the ropes).

[vsavkin]

No worries