README updates and contribution quide

README.md

@@ -1,6 +1,8 @@
 <p align="center"><img src="https://user-images.githubusercontent.com/1402048/52643646-c2102980-2edd-11e9-8c37-b72f3c89a640.png" data-canonical-src="![TTS banner](https://user-images.githubusercontent.com/1402048/52643646-c2102980-2edd-11e9-8c37-b72f3c89a640.png =250x250)
 " width="320" height="95" /></p>
 
+<img src="https://travis-ci.org/mozilla/TTS.svg?branch=dev"/>
+
 This project is a part of [Mozilla Common Voice](https://voice.mozilla.org/en). TTS aims a deep learning based Text2Speech engine, low in cost and high in quality. To begin with, you can hear a sample generated voice from [here](https://soundcloud.com/user-565970875/commonvoice-loc-sens-attn).
 
 TTS includes two different model implementations which are based on [Tacotron](https://arxiv.org/abs/1703.10135) and [Tacotron2](https://arxiv.org/abs/1712.05884). Tacotron is smaller, efficient and easier to train but Tacotron2 provides better results, especially when it is combined with a Neural vocoder. Therefore, choose depending on your project requirements.
@@ -109,6 +111,16 @@ You can also enjoy Tensorboard,  if you point Tensorboard argument```--logdir```
 ## Testing
 Best way to test your network is to use Notebooks under ```notebooks``` folder.
 
+## Contribution guidelines
+This repository is governed by Mozilla's code of conduct and etiquette guidelines. For more details, please read the [Mozilla Community Participation Guidelines.](https://www.mozilla.org/about/governance/policies/participation/)
+
+Please send your Pull Request to ```dev``` branch. Before making a Pull Request, check your changes for basic mistakes and style problems by using a linter. We have cardboardlinter setup in this repository, so for example, if you've made some changes and would like to run the linter on just the changed code, you can use the follow command:
+
+```bash
+pip install pylint cardboardlint
+cardboardlinter --refspec master
+```
+
 ## Contact/Getting Help
 - [Wiki](https://github.com/mozilla/TTS/wiki)