adding app.py to solved the challenge

Cheange after review from Aviad, used with.. open, variable names cheanged, pass flake8 lint rules

broke the last print into 2 prints commands

added yml for testing flake8 on travis CI

comiited the wrong file before

Delete app.py

only want on this PR .travis.yml

.travis.yml

@@ -0,0 +1,11 @@
+language: python
+python:
+  - "3.6"
+  - "3.7"
+  - "3.8"
+
+install:
+  - pip install flake8
+
+script:
+  - flake8 .