CI, resolves #3

+# Continuous Integration
+
+Due to creativecreatorormaybenot lacking knowledge, the current Travis CI implementation is based on [provider's setup](https://github.com/rrousselGit/provider/blob/09c7fdebc382121f1a497180a6fe393a5e54b904/.travis.yml). 

+set -e
+cd $1
+flutter packages get
+flutter format --set-exit-if-changed .
+flutter analyze --no-current-package .
+cd example
+flutter drive --target=test_driver/app.dart
+cd -

+language: bash
+os:
+  - osx
+env:
+  - FLUTTER_CHANNEL="stable"
+  - FLUTTER_CHANNEL="master"
+sudo: false
+before_script:
+  - cd ..
+  - git clone https://github.com/flutter/flutter.git -b $FLUTTER_CHANNEL
+  - export PATH=$PATH:$PWD/flutter/bin:$PWD/flutter/bin/cache/dart-sdk/bin
+  - cd -
+  - flutter doctor
+script:
+  - set -e
+  - ./scripts/drive.sh
+matrix:
+  fast_finish: true
+cache:
+  directories:
+    - $HOME/.pub-cache