Merge pull request #31 from realpython/jima/fix_issue30

Removing pkg-resources=0.0.0 from requirements.txt file.  This is an …

Author: dbader

concurrency-overview/requirements.txt

@@ -20,7 +20,6 @@ multidict==4.4.2
 multio==0.2.3
 outcome==0.1.0
 pathlib2==2.3.2
-pkg-resources==0.0.0
 pluggy==0.7.1
 py==1.6.0
 pycodestyle==2.3.1