Add code coverage

.travis.yml

@@ -13,7 +13,7 @@ install:
   - pip install -rdev-requirements.txt
 
 script:
-    - py.test -v -s tests
+    - py.test -v -s tests --cov gns3server --cov-report term-missing
 
 #branches:
 #  only:
@@ -28,3 +28,5 @@ notifications:
 #    on_success: change
 #    on_failure: always
 
+after_success:
+  - coveralls

dev-requirements.txt

@@ -5,3 +5,5 @@ pytest==2.6.4
 pep8==1.5.7
 pytest-timeout
 pytest-capturelog
+pytest-cov
+python-coveralls