Updated required metis version for networkx 2.0 compability.

Former-commit-id: edbe7d65201f748b292ebd1c5dafb1ee591c3a58

.gitignore

@@ -12,4 +12,4 @@ PKG-INFO
 # PyCharm
 .idea
 **/.idea/workspace.xml
-**/.idea/tasks.xml
\ No newline at end of file
+**/.idea/tasks.xml

requirements.txt

-metis
+metis>=0.2a3
 lxml
 tabulate
 flask

setup.py

@@ -28,7 +28,7 @@ setup(name='kadmos',
       license='Apache Software License',
       packages=find_packages(),
       install_requires=[
-            'metis',
+            'metis>=0.2a3',
             'lxml',
             'tabulate',
             'flask',