When we run a tower job from jenkins, we are seeing this error message:

ERROR: Unable to request job template invocation Tower received a bad request (400 response code)
{"credential":["Incorrect type. Expected pk value, received unicode."],"credentials":["Incorrect type. Expected pk value, received unicode."]}

we are running the job with the following:

ansibleTower towerServer: 'tower', jobTemplate: '55',
inventory: '14', credential: '12', importTowerLogs: true

Does the credential need to be an integer? It seems like it is sending the credential the wrong way over the API.