Merge branch 'feat/01_models' into feat/02_repositories

Author: Esteban Echeverry

.travis.yml

@@ -0,0 +1,9 @@
+language: python
+python:
+  - "3.5"
+install:
+  - pip install -r requirements.txt
+script:
+  - pytest -s --cov-report term-missing --cov-branch --cov taskit tests
+after_success:
+  - codecov