Test different subplot keyword
Test different subplot keyword

Matplotlib changed the axisbg parameter in 2.0. Test the projection
instead (which is probably more useful).
Fixes #1098

anntzer/seaborn,phobson/seaborn,petebachant/seaborn,arokem/seaborn,mwaskom/seaborn,arokem/seaborn,lukauskas/seaborn,sauliusl/seaborn,phobson/seaborn,mwaskom/seaborn,JWarmenhoven/seaborn,anntzer/seaborn,lukauskas/seaborn