upgrade rspec to 2.99 to get deprecation warnings for rspec 3
fix some rspec deprecation warnings: rename be_true => be_truthy, be_false => be_falsey
rspec: fix remaining deprecation warnings using 'its'
Rename Gemfile.common => Gemfile.common.rb
upgrade to rspec 3.0
rspec: convert mock expectations into new syntax to avoid deprecation warnings
Update changelog
upgrade to rspec 3.1.0