ci: Use my fork of luacov-coveralls to test GH Actions changes

Author: alerque

.github/workflows/busted.yml

@@ -27,7 +27,7 @@ jobs:
         luarocks install dkjson
         luarocks install luafilesystem
         luarocks install lua-path
-        luarocks install https://luarocks.org/manifests/moteus/luacov-coveralls-scm-0.rockspec
+        luarocks install https://raw.githubusercontent.com/alerque/luacov-coveralls/master/rockspecs/luacov-coveralls-scm-0.rockspec
     - name: Run Busted Tests
       run: busted -c -v
     - name: Report Test Coverage