Refactoring: Made complete codebase PEP8 compatible.

Only PEP8 rule E501 (line too long) is not yet reflected
by this change.

The patch also adds automated code style checks to the
CI test stage using flake8.
It will let the tests fail if there is a code style
violation.

Change-Id: I90956dd424a46691546ef720351757d3c43451a7
Signed-off-by: peusterm <manuel.peuster@uni-paderborn.de>
diff --git a/src/emuvim/cli/rest/datacenter.py b/src/emuvim/cli/rest/datacenter.py
index 651c55c..f4f92c3 100755
--- a/src/emuvim/cli/rest/datacenter.py
+++ b/src/emuvim/cli/rest/datacenter.py
@@ -1,30 +1,28 @@
-"""
-Copyright (c) 2015 SONATA-NFV and Paderborn University
-ALL RIGHTS RESERVED.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-
-Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
-nor the names of its contributors may be used to endorse or promote
-products derived from this software without specific prior written
-permission.
-
-This work has been performed in the framework of the SONATA project,
-funded by the European Commission under Grant number 671517 through
-the Horizon 2020 and 5G-PPP programmes. The authors would like to
-acknowledge the contributions of their colleagues of the SONATA
-partner consortium (www.sonata-nfv.eu).
-"""
+# Copyright (c) 2015 SONATA-NFV and Paderborn University
+# ALL RIGHTS RESERVED.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Neither the name of the SONATA-NFV, Paderborn University
+# nor the names of its contributors may be used to endorse or promote
+# products derived from this software without specific prior written
+# permission.
+#
+# This work has been performed in the framework of the SONATA project,
+# funded by the European Commission under Grant number 671517 through
+# the Horizon 2020 and 5G-PPP programmes. The authors would like to
+# acknowledge the contributions of their colleagues of the SONATA
+# partner consortium (www.sonata-nfv.eu).
 from requests import get
 from tabulate import tabulate
 import pprint
@@ -32,6 +30,7 @@
 
 pp = pprint.PrettyPrinter(indent=4)
 
+
 class RestApiClient():
 
     def __init__(self):
@@ -44,40 +43,41 @@
         else:
             print("Command not implemented.")
 
-    def list(self,args):
+    def list(self, args):
         list = get('%s/restapi/datacenter' % args.get('endpoint')).json()
         table = []
         for d in list:
             # for each dc add a line to the output table
             if len(d) > 0:
                 table.append([d.get("label"),
-                           d.get("internalname"),
-                           d.get("switch"),
-                           d.get("n_running_containers"),
-                           len(d.get("metadata"))])
+                              d.get("internalname"),
+                              d.get("switch"),
+                              d.get("n_running_containers"),
+                              len(d.get("metadata"))])
         headers = ["Label",
-               "Internal Name",
-               "Switch",
-               "# Containers",
-               "# Metadata Items"]
-        print (tabulate(table, headers=headers, tablefmt="grid"))
+                   "Internal Name",
+                   "Switch",
+                   "# Containers",
+                   "# Metadata Items"]
+        print(tabulate(table, headers=headers, tablefmt="grid"))
 
-    def status(self,args):
-        list = get('%s/restapi/datacenter/%s' % ( args.get("endpoint"), args.get("datacenter"))).json()
+    def status(self, args):
+        list = get('%s/restapi/datacenter/%s' %
+                   (args.get("endpoint"), args.get("datacenter"))).json()
         table = []
         table.append([list.get('label'),
-                  list.get('internalname'),
-                  list.get('switch'),
-                  list.get('n_running_containers'),
-                  len(list.get('metadata'))])
+                      list.get('internalname'),
+                      list.get('switch'),
+                      list.get('n_running_containers'),
+                      len(list.get('metadata'))])
 
         headers = ["Label",
-               "Internal Name",
-               "Switch",
-               "# Containers",
-               "# Metadata Items"]
+                   "Internal Name",
+                   "Switch",
+                   "# Containers",
+                   "# Metadata Items"]
 
-        print (tabulate(table, headers=headers, tablefmt="grid"))
+        print(tabulate(table, headers=headers, tablefmt="grid"))
 
 
 parser = argparse.ArgumentParser(description='son-emu-cli datacenter')
@@ -98,4 +98,3 @@
     args = vars(parser.parse_args(argv))
     c = RestApiClient()
     c.execute_command(args)
-