PARQUET-50: Re-Enable the semver enforcer

Author: Alex Levenson <alexlevenson@twitter.com>

Closes #37 from isnotinvain/alexlevenson/fix-backwards-compat-check and squashes the following commits:

c91335c [Alex Levenson] Bump version to 1.6.1 to make semver enforcer happy
c09c8c1 [Alex Levenson] PARQUET-50: Re-Enable the semver enforcer