Added contributing guidelines.
Added contributing guidelines.
SteveFortune/ocmock,dhardiman/ocmock,Lightricks/ocmock,firebase/ocmock,imhuntingwabbits/ocmock,erikdoe/ocmock,erikdoe/ocmock,erikdoe/ocmock,Lightricks/ocmock,BohdanOrlov/ocmock,Lightricks/ocmock,NextThought/ocmock,Lightricks/ocmock,erikdoe/ocmock