Update .travis.yml

Author: DomAmato

.travis.yml

@@ -1,9 +1,28 @@
 sudo: required
 language: python
-python:
-- '2.7'
-install: pip install -r requirements.txt
-script: make test
+os: linux
+dist: xenial          # required for Python >= 3.7
+
+matrix:
+  include:
+    - stage: lint
+      python: 3.7
+      name: 'lint'
+      script: 
+        - pip install -r requirements.txt
+        - pip install pylint
+        - pylint -rn --errors-only ./Hologram
+    
+    - stage: test
+      python: 3.7
+      name: 'test python 3'
+      script:      
+        - pip install .
+        - pip install coveralls
+        - rm -r tests/radius
+        - coverage run --source Hologram -m py.test
+        - coveralls
+
 notifications:
   email: false
   slack: