Adapt for hspec-wai-0.4.*
Bump text upper version bounds
Fix travis build
Merge pull request #119 from RyanGlScott/master

Bump text upper version bounds
Require hspec-wai >= 0.4.1
Remove the use of the LambdaCase extension

The extension is available only in GHC 7.6+, which unnecessarily
prevents compiling scotty on older versions (for example Debian Wheezy
has 7.4).

Also simplify takeMVar ... putMVar using modifyMVar.