add linter to CI (#41)

- create continuous integration for linter
- move --fix out of the main `npm run lint` script. moved to `npm run lint:fix`. CI now runs `npm run lint`, and should not be changing any files, just checking

.github/workflows/linter.yml

@@ -0,0 +1,15 @@
+name: Linter
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - run: npm ci
+    - run: npm run lint

package.json

@@ -10,11 +10,15 @@
     "test:delay": "mocha --delay --require @babel/register --reporter list",
     "lint:es5": "jshint \"dist/loader-dev.js\" \"dist/loader-gadget.js\"",
     "lint:es5:dev": "jshint \"dist/loader-dev.js\"",
-    "lint:css": "stylelint \"styles-src/**/*.css\" --fix",
-    "lint:es6": "eslint \"xfdcloser-src/**/*.js\" \"test/*\" --fix",
-    "lint:bin": "eslint \"bin/*.js\" --fix --env node",
+    "lint:css": "stylelint \"styles-src/**/*.css\"",
+    "lint:es6": "eslint \"xfdcloser-src/**/*.js\" \"test/*\"",
+    "lint:bin": "eslint \"bin/*.js\" --env node",
     "lint": "npm run lint:es6 && npm run lint:es5 && npm run lint:css",
     "lint:dev": "npm run lint:es6 && npm run lint:es5:dev && npm run lint:css",
+    "lint:css:fix": "stylelint \"styles-src/**/*.css\" --fix",
+    "lint:es6:fix": "eslint \"xfdcloser-src/**/*.js\" \"test/*\" --fix",
+    "lint:bin:fix": "eslint \"bin/*.js\" --fix --env node",
+    "lint:fix": "npm run lint:es6:fix && npm run lint:bin:fix && npm run lint:css:fix",
     "globals:node": "concat-cli -f \"globals-src/comment.js\" \"globals-src/node.js\" -o \"globals.js\"",
     "globals:window": "concat-cli -f \"globals-src/comment.js\" \"globals-src/window.js\" -o \"globals.js\"",
     "build:loader:dev": "concat-cli -f \"loader-src/loader-dev-top.js.txt\" \"loader-src/loader-core.js.txt\" \"loader-src/loader-dev-bottom.js.txt\" -o dist/loader-dev.js",