Reduce code + Remove github workflow

.github/workflows/luacheck.yml

@@ -1,21 +0,0 @@
-name: Luacheck
-
-on: [push, pull_request]
-
-jobs:
-
-  luacheck:
-    runs-on: ubuntu-20.04
-    steps:
-    - name: Checkout
-      uses: actions/checkout@v2
-    - name: Setup ‘lua’
-      uses: leafo/gh-actions-lua@v8
-      with:
-        luaVersion: 5.1
-    - name: Setup ‘luarocks’
-      uses: leafo/gh-actions-luarocks@v4
-    - name: Setup ‘luacheck’
-      run: luarocks install luacheck
-    - name: Run ‘luacheck’ linter
-      run: luacheck .