CI: drop deploy step

RPM/DEB packages are discontinued (they're unlikely to come back). Users
are encouraged to use PyPI instead.

.travis.yml

@@ -15,19 +15,3 @@ install:
 script:
   - python setup.py build
   - python setup.py test
-before_deploy:
-  - deactivate
-  - python3 setup.py bdist_rpm
-  - dpkg-buildpackage -uc -us
-  - cp ../*.deb dist/
-deploy:
-  provider: releases
-  api_key: $GH_TOKEN
-  file_glob: true
-  file:
-  - dist/stcgal*_all.deb
-  - dist/stcgal*.noarch.rpm
-  skip_cleanup: true
-  on:
-    tags: true
-    python: "3.4"