travis: Add default profile with example creds

.travis.yml

@@ -16,6 +16,9 @@ install:
   - echo '[aws-stage]' > ~/.aws/credentials
   - echo 'aws_access_key_id = AKIAIOSFODNN7EXAMPLE' >> ~/.aws/credentials
   - echo 'aws_secret_access_key = wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY' >> ~/.aws/credentials
+  - echo '[default]' >> ~/.aws/credentials
+  - echo 'aws_access_key_id = AKIAIOSFODNN7EXAMPLE' >> ~/.aws/credentials
+  - echo 'aws_secret_access_key = wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY' >> ~/.aws/credentials
 
 script:
   - tox -e $TOX_ENV