Test case added

#1. InitWithDataTests.m file added
#2. testForNilInputFromData failed because no error - fixed
More tests added

added methods for checking  initWithData
Just copied from SimpleDataErrorTests and replaced
stringWithContentsOfFile with dataWithContentsOfFile and init with data
accordingly
Added methods
#1. testErrorsInNestedModelsDictionary
#2. testErrorsInNestedModelsArray
#3. testMissingKeysError
#4. testTypeMismatchErrorImages
#5. testTypeMismatchErrorImagesObject