Merge pull request #39 from opencobra/dependabot/pip/pillow-6.2.0

Bump pillow from 5.3.0 to 6.2.0

Author: gregmedlock

requirements.txt

@@ -45,7 +45,7 @@ pandocfilters==1.4.2
 parso==0.3.1
 pexpect==4.6.0
 pickleshare==0.7.5
-Pillow==5.3.0
+Pillow==6.2.0
 pipdeptree==0.13.1
 pipenv==2018.10.13
 ply==3.11