chore: Remove Travis CI (aws#314)

Moving to CodeBuild for CI

Author: seebees

.travis.yml

@@ -18,12 +18,6 @@ aws-encryption-sdk
    :target: https://aws-encryption-sdk-python.readthedocs.io/en/stable/
    :alt: Documentation Status
 
-.. image:: https://travis-ci.org/aws/aws-encryption-sdk-python.svg?branch=master
-   :target: https://travis-ci.org/aws/aws-encryption-sdk-python
-
-.. image:: https://ci.appveyor.com/api/projects/status/p3e2e63gsnp3cwd8/branch/master?svg=true
-   :target: https://ci.appveyor.com/project/mattsb42-aws/aws-encryption-sdk-python-qvyet/branch/master
-
 The AWS Encryption SDK for Python provides a fully compliant, native Python implementation of the `AWS Encryption SDK`_.
 
 The latest full documentation can be found at `Read the Docs`_.