Compiled conductor lint classes have different class version

[mpetrychko]

We are having this error when trying to build our project:
java.lang.UnsupportedClassVersionError: com/bluelinelabs/conductor/lint/ControllerIssueDetector has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0

Having looked at the aar archive here I found that IssueRegistry has class file version 52, and ControllerIssueDetector has 55.

Is there any reason for them to have different versions? This probably won't fix our issue but I'm still curious.