The changes introduced in
DCOS_OSS-4464 changed naming of the EQ operator to IS. When reading a Metronome placement constraint, EQ will be converted to IS.
However, the JSON schemas for both v0 and v1 list valid enum values as "EQ", "LIKE", "UNLIKE", which means trying to create a job with an IS operator will fail. This also means that POSTing the JSON fetched via GET will fail, which is definitely a breaking chage.
We need to at least add IS as a valid operator.
We should evaluate whether we want to treat EQ as a standalone operator for 0.6.x (that will be converted to an underlying Marathon IS), so that tools that only expect/handle EQ will not break when reading JSON output from Metronome. I don't believe that's warranted.