ConfigReader needs to be defined with a covariant type parameter

[Jed Wesley-Smith]

For compatibility with the scalaz 7.0.x variance scheme, to use it in a monad transformer (specifically EitherT) it needs to be defined as ConfigReader[+_]

[Jed Wesley-Smith]

fixed in: https://bitbucket.org/atlassian/kadai/commits/bb3683fdce7969e68efd09b37ebf90ca2079fb2c

released in 1.3.0