(PUP-3013) Accept. tests - 3.7 PMT updates build

This commit adds additional acceptance test coverage for updates
the puppet module build command. These tests validate the
following:

    * detection of symlinks in module
    * detection of file changes created by build process
Merge pull request #2976 from johnduarte/pmt-build-acceptance-3.7

(PUP-3013) Accept. tests - 3.7 PMT updates build