Updates for # in PVL. (#195)

* Fixes 194 and simplifies serial generation.

* Updates CTX label to include a comment.

* Fixces SQLAlchemy Bind for pytests

* Updates GDAL dependency

* Fixes pandas import for frame_equal test

* Fixes isis serial number generation.

* Fixes proj string on test data.

* Fixes conditional imports for gdal, osr, ogr.

* Fixes projection test for gdal > 3.

* Upates CHANGELOG to include testing fixes.