Rename spec_helper -> helper
Add Coveralls for code coverage reporting
Add coveralls gem to Rack 1.3 Gemfile
Remove warnings "`&' interpreted as argument prefix"
Remove warnings "method redefined"
Remove warnings "instance variable @{ivar} not initialized"
Remove warnings "instance variable @{ivar} not initialized" in spec
Remove warnings "assigned but unused variable" in spec
Block in Strategy.configure can return nil
Change response type from default to text/html

Closes #673.
Merge pull request #672 from nashbridges/strategy-configure

Block in Strategy.configure can return nil
got the hooks working, but insofar as testing anything other than just creating the hooks, I'll have to get to that later
adding the hooks to mock request call and mock callback call
adding specs for the hooks to ensure that they are running
Merge branch 'hooks' of github.com:cromulus/omniauth into hooks