refactor: convert test cases to pytest (#194)

- Rename test file names to use underscores
- Run nose2pytest against all test files
- Run isort against all test files
- Add __init__.py to tests directory
- Add module docstrings
- Remove imports from __future__
- Remove utf8 encoding declaration; not needed in Python3
- Get tests to pass

Author: giovtorres

tests/__init__.py

@@ -1,6 +1,8 @@
-# -*- coding: utf-8 -*-
+"""Common utilities for test cases."""
+
 import subprocess
 
+
 def scontrol_show(subcommand, *args):
     """Return output of 'scontrol show <subcommand>'"""
     if args:
@@ -9,12 +11,13 @@ def scontrol_show(subcommand, *args):
         extra_args = ""
 
     sctl = subprocess.Popen(
-        ["scontrol", "-d", "show", subcommand, extra_args],
-        stdout=subprocess.PIPE
+        ["scontrol", "-d", "show", subcommand, extra_args], stdout=subprocess.PIPE
     ).communicate()
 
     sctl_stdout = sctl[0].strip().decode("UTF-8", "replace").split()
-    sctl_dict = dict((value.split("=")[0], value.split("=")[1] if len(value.split("=")) > 1 else '')
-                     for value in sctl_stdout)
+    sctl_dict = dict(
+        (value.split("=")[0], value.split("=")[1] if len(value.split("=")) > 1 else "")
+        for value in sctl_stdout
+    )
 
     return sctl_dict