Feature/1.0.1 (#3)
* Added tests for JsonObject and fixed a couple bugs that the tests found.
* Added tests for JsonArray.
Improved error messaging for when JsonElement type is not of desired type.
* Small helpers added to JsonArray and JsonObject to convert to JsonElement.
* Added JsonMapper interface with some default methods implemented for converting between JsonObject or JsonArray into java objects
* SolaJson now has several methods that utilize new JsonMapper.
Fixed another bug in JsonElement.