Continuous Integration using @PlatformIO and @travis-ci

@PlatformIO (an open source ecosystem for IoT development) in pair with @travis-ci proposes to apply continuos integration for embedded projects in a few clicks.

* Official Travis CI Documentation for PlatformIO: https://docs.travis-ci.com/user/integration/platformio/
* PlatformIO documentation for Travis CI: http://docs.platformio.org/en/latest/ci/travis.html

Please enable Travis.CI for this project http://docs.travis-ci.com/user/getting-started/#To-get-started-with-Travis-CI%3A (steps 1, 2, 5)

What is more, you can add badge with build status to your README

**Markdown**
```
[![Build Status](https://travis-ci.org/LowPowerLab/SPIFlash.svg?branch=master)](https://travis-ci.orgLowPowerLab/SPIFlash)
```

**RST**
```
.. image:: https://travis-ci.org/LowPowerLab/SPIFlash.svg?branch=master
    :target: https://travis-ci.org/LowPowerLab/SPIFlash
```

.travis.yml

@@ -0,0 +1,18 @@
+language: python
+python:
+    - "2.7"
+
+# Cache PlatformIO packages using Travis CI container-based infrastructure
+sudo: false
+cache:
+    directories:
+        - "~/.platformio"
+
+env:
+    - PLATFORMIO_CI_SRC=examples/SPIFlash_ReadWrite/SPIFlash_ReadWrite.ino
+
+install:
+    - pip install -U platformio
+
+script:
+    - platformio ci --lib=. --board=moteino --board uno --board=moteinomega