Make `verify` check both server and kernel environments
MODIFY
tests/venv/py2-with-kernel-requirements/verify
tests/venv/py2-with-kernel-requirements/verify
#!/usr/bin/env python2
+import os
import sys
print(sys.version_info)
assert sys.version_info[:2] == (2, 7)
import numpy
+
+try:
+ import nbgitpuller
+except ImportError:
+ pass
+else:
+ raise Exception("'nbgitpuller' shouldn't have been installed from requirements3.txt")
+
+# Python 3 is the executable used for the notebook server, this should
+# have nbgitpuller installed
+os.system("python3 -c 'import nbgitpuller'")

Make `verify` check both server and kernel environments