added url encoded String Injection
switched to attempt from Try
added json4s injections
added Json4sInjectionLaws.scala
added return type to all public val/def
changed injections to allow passing json4s format
added package object
switched to anyref
removed T
reformat the code
Merge pull request #157 from MansurAshraf/feature/json4s

Added Json4s Injections
Merge pull request #156 from MansurAshraf/develop

added url encoded String Injection