Use main branch for CI/CD

Author: acoburn

.travis.yml

@@ -2,6 +2,10 @@ language: python
 python:
     - "3.4"
 
+branches:
+  only:
+    - main
+
 before_script:
     - flake8 .
 

README.rst

@@ -8,13 +8,13 @@ Python-based Linked Data Notifications libraries
    :alt: Version
 
 
-.. image:: https://travis-ci.com/trellis-ldp/py-ldnlib.svg?branch=master
+.. image:: https://travis-ci.com/trellis-ldp/py-ldnlib.svg?branch=main
    :target: https://travis-ci.com/trellis-ldp/py-ldnlib
    :alt: Build Status
 
 
-.. image:: https://coveralls.io/repos/github/trellis-ldp/py-ldnlib/badge.svg?branch=master
-   :target: https://coveralls.io/github/trellis-ldp/py-ldnlib?branch=master
+.. image:: https://coveralls.io/repos/github/trellis-ldp/py-ldnlib/badge.svg?branch=main
+   :target: https://coveralls.io/github/trellis-ldp/py-ldnlib?branch=main
    :alt: Coverage Status