Test against Rails 4.2 (beta)
Update the bundler and rake gem dependency version requirements
Lock the development rails gem dependency to < 4.3
Track test coverage on every build
Add changelog entries for version 1.0.0.rc2

[ci skip]
Use the flat, squared readme badge style

[ci skip]
Add an upgrade section to the readme

[ci skip]
Use a .rspec file
Move the missing key error message into the error class
Update the missing key error copy to be consistent with missing keys
Bump to version 1.0.0

[ci skip]
Remove leftover legacy documentation note from the readme

[ci skip]
Add print cli command