Bumping pytest version to fix unresolvable pluggy dependency (kensho-technologies#151)

Author: jmeulemans

Pipfile

@@ -11,7 +11,7 @@ isort = "==4.3.4"
 pydocstyle = "==2.1.1"
 pylint = "==1.8.2"
 pyorient = "==1.5.5"
-pytest = "==3.4.1"
+pytest = "==4.0.2"
 pytest-cov = "==2.5.1"
 snapshottest = "==0.5.0"