Prevent Constant propagation errors and add Mockito

Prevent a constant propagation error which was occurring because
the consensus was being returned as null. Removed a "debug point"
from Caleb ('wtf?') and added a test case. Needed to import the
dependancy of Mockito to the project so I could Mock out
the surrounding code for a proper unit test, also needed to add
in some dependency inject to get away from using ConstantBuilder
only as a static class.
wtf indeed.