added coveralls to ci pipeline

.travis.yml

@@ -14,3 +14,5 @@ install:
   - pip install -r requirements.txt
 script:
   - coverage run -m unittest discover
+after_success:
+  - coveralls

README.md

@@ -1,6 +1,7 @@
 # YouTube Transcript/Subtitle API (including automatically generated subtitles)
 
 [![Build Status](https://travis-ci.org/jdepoix/youtube-transcript-api.svg)](https://travis-ci.org/jdepoix/youtube-transcript-api)
+[![Coverage Status](https://coveralls.io/repos/github/jdepoix/youtube-transcript-api/badge.svg?branch=master)](https://coveralls.io/github/jdepoix/youtube-transcript-api?branch=master)
 [![MIT license](http://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat)](http://opensource.org/licenses/MIT)
 [![image](https://img.shields.io/pypi/v/youtube-transcript-api.svg)](https://pypi.org/project/youtube-transcript-api/)
 [![image](https://img.shields.io/pypi/pyversions/youtube-transcript-api.svg)](https://pypi.org/project/youtube-transcript-api/)

requirements.txt

@@ -3,4 +3,5 @@ requests
 # testing
 mock
 httpretty
-coverage
+coverage
+coveralls

setup.py

@@ -46,6 +46,7 @@ setuptools.setup(
         'mock',
         'httpretty',
         'coverage',
+        'coveralls',
     ],
     test_suite='setup.get_test_suite',
     entry_points={