create model package and move Link and LinkFields into it
rename RestApi to SparkRestApi
create RestApi interface
SparkRestApi implements RestApi
use RestApi interface in main()
refactor PostLinkRoute
rename Transformator to JSONTransformator
refactor methodnames in JSONTransformator
put SuppressWarnigns unchecked annotation on the class definition of JSONTransformator
refactor JSONTransformator
fix TestRestApi setup
return statuscode 400 if no password was provided for post request
test changed implementation of PostLinkRoute
create class for string constants to use as error messages in the http response
use the error message constants in PostLinkRoute and its tests
add constant for missing payload error msg
return error on missing payload in PostLinkRoute
refactor PostLinkRoute
add auth and missing payload tests to TestRestApi integration tests
add IntegrationTest category to TestRestApi