Explicitly setting MANIFEST, a nightmare to get config values respected

MANIFEST.in

@@ -1,13 +1,16 @@
 recursive-include mopidy_iris/static *
 recursive-include mopidy_iris *.py
 recursive-include docs *
-recursive-include __tests__ *.py
-recursive-include __tests__ *.js
-recursive-include __mocks__ *.js
+recursive-include __tests__ *
+recursive-include __mocks__ *
 include mopidy_iris/ext.conf
 include mopidy_iris/system.sh
 include IRIS_VERSION
 include Dockerfile
 include pyproject.toml
 include screenshot.jpg
-include tox.ini
+include tox.ini
+recursive-exclude src *
+exclude .jshintrc
+exclude .babelrc
+exclude jest.config.js