Applied pylint and added a make lint command

.travis.yml

@@ -11,4 +11,6 @@ install:
   - make install
 
 script:
+  - make lint
+  - make nosetest
   - make docker_test

setup.cfg

@@ -0,0 +1,5 @@
+[pylint.MASTER]
+jobs=4
+
+[pylint.'MESSAGES CONTROL']
+disable = R,C,W5103

vdt/simpleaptrepo/repo.py

@@ -12,7 +12,7 @@ def create_gpg_key(output_command):
     try:
         output_command(subprocess.check_output(cmd, shell=True))
     except subprocess.CalledProcessError as e:
-        raise ValueError(e)
+        raise ValueError from e
 
 
 def export_pubkey(path, gpgkey, output_command):

vdt/simpleaptrepo/tests/test_cli.py

@@ -1,7 +1,4 @@
-try:
-    import ConfigParser  # python 2
-except:
-    import configparser as ConfigParser  # python 3
+import configparser as ConfigParser
 
 import os
 import shutil
@@ -181,7 +178,7 @@ def test_list_repos(self):
             self.assertEqual(result.output, LIST_REPOS_OUTPUT)
 
     @mock.patch("subprocess.check_output", return_value="Mocked output")
-    def test_update_repo(self, mock_subprocess=None):
+    def test_update_repo(self, mock_subprocess=None):  # pylint: disable=W0613
         runner = CliRunner()
 
         with runner.isolated_filesystem():

vdt/simpleaptrepo/tests/test_utils.py

@@ -4,24 +4,24 @@
 
 
 def mock_dist_osx():
-    return ("Mac OSX", "10.10.5", "Yosemity")
+    return "macOS-10.14.6-x86_64-i386-64bit"
 
 
 def mock_dist_ubuntu():
-    return ("Ubuntu", "12.04", "precise")
+    return "Linux-4.10.0-40-generic-x86_64-with-Ubuntu-16.04-xenial"
 
 
 def mock_dist_debian():
-    return ("debian", "8.6", "")
+    return "Linux-4.10.0-40-generic-x86_64-with-Debian-10"
 
 
 class TestUtils(unittest.TestCase):
     def test_platform_is_debian(self):
-        utils.platform.dist = mock_dist_osx
+        utils.platform.platform = mock_dist_osx
         self.assertFalse(utils.platform_is_debian())
 
-        utils.platform.dist = mock_dist_ubuntu
+        utils.platform.platform = mock_dist_ubuntu
         self.assertTrue(utils.platform_is_debian())
 
-        utils.platform.dist = mock_dist_debian
+        utils.platform.platform = mock_dist_debian
         self.assertTrue(utils.platform_is_debian())

vdt/simpleaptrepo/utils.py

@@ -26,5 +26,5 @@ def write_to_stdout(message):
 
 
 def platform_is_debian():
-    current_platform = platform.dist()[0].lower()
-    return current_platform in ["ubuntu", "debian"]
+    current_platform = platform.platform().lower()
+    return "ubuntu" in current_platform or "debian" in current_platform