Merge pull request #21 from guyskk/pyup-update-codecov-2.0.10-to-2.0.13

Update codecov to 2.0.13

requirements.txt

@@ -4,7 +4,7 @@ tox==2.9.1
 flake8==3.5.0
 pytest==3.3.2
 pytest-cov==2.5.1
-codecov==2.0.10
+codecov==2.0.13
 pytest-httpbin==0.3.0
 invoke==0.22.0
 twine==1.9.1