Switched to using .js files for eslint

- Using JS files to configure eslint gives us more power, e.g. being able to calculate paths
- We already use JS in pretty much every other repo we own, including admin... it's just Ghost we don't, and it's time!

.eslintrc.js

@@ -0,0 +1,18 @@
+module.exports = {
+    env: {
+        es6: true,
+        node: true
+    },
+    plugins: ['ghost'],
+    extends: [
+        'plugin:ghost/node'
+    ],
+    rules: {
+        // @TODO: remove this rule once it's turned into "error" in the base plugin
+        'no-shadow': 'error',
+        'no-var': 'error',
+        'one-var': [2, 'never'],
+        // @TODO: enable this for all components once it gets a bit quieter
+        'ghost/ghost-custom/no-cross-requires': ['warn', {shared: true, server: false, frontend: false}]
+    }
+};

.eslintrc.json

@@ -1,20 +0,0 @@
-{
-    "env": {
-        "es6": true,
-        "node": true
-    },
-    "plugins": [
-        "ghost"
-    ],
-    "extends": [
-        "plugin:ghost/node"
-    ],
-    "rules": {
-        // @TODO: remove this rule once it's turned into "error" in the base plugin
-        "no-shadow": "error",
-        "no-var": "error",
-        "one-var": [2, "never"],
-        // @TODO: enable this for all components once it gets a bit quieter
-        "ghost/ghost-custom/no-cross-requires": ["warn", {"shared": true, "server": false, "frontend": false}]
-    }
-}

test/.eslintrc.js

@@ -0,0 +1,32 @@
+module.exports = {
+    env: {
+        es6: true,
+        node: true,
+        mocha: true
+    },
+    plugins: [
+        'ghost'
+    ],
+    extends: [
+        'eslint:recommended',
+        'plugin:ghost/test'
+    ],
+    rules: {
+        // TODO: remove this rule once it's turned into "error" in the base plugin
+        'no-shadow': 'error',
+
+        // these rules were were not previously enforced in our custom rules,
+        // they're turned off here because they _are_ enforced in our plugin.
+        // TODO: remove these custom rules and fix the problems in test files where appropriate
+        camelcase: 'off',
+        'no-prototype-builtins': 'off',
+        'no-unused-vars': 'off',
+        'no-useless-escape': 'off',
+
+        // TODO: remove these custom rules and fix problems in test files
+        'ghost/mocha/max-top-level-suites': 'off',
+        'ghost/mocha/no-identical-title': 'off',
+        'ghost/mocha/no-setup-in-describe': 'off',
+        'ghost/mocha/no-sibling-hooks': 'off'
+    }
+};

test/.eslintrc.json

@@ -1,32 +0,0 @@
-{
-    "env": {
-        "es6": true,
-        "node": true,
-        "mocha": true
-    },
-    "plugins": [
-        "ghost"
-    ],
-    "extends": [
-        "eslint:recommended",
-        "plugin:ghost/test"
-    ],
-    "rules": {
-        // TODO: remove this rule once it's turned into "error" in the base plugin
-        "no-shadow": "error",
-
-        // these rules were were not previously enforced in our custom rules,
-        // they're turned off here because they _are_ enforced in our plugin.
-        // TODO: remove these custom rules and fix the problems in test files where appropriate
-        "camelcase": "off",
-        "no-prototype-builtins": "off",
-        "no-unused-vars": "off",
-        "no-useless-escape": "off",
-
-        // TODO: remove these custom rules and fix problems in test files
-        "ghost/mocha/max-top-level-suites": "off",
-        "ghost/mocha/no-identical-title": "off",
-        "ghost/mocha/no-setup-in-describe": "off",
-        "ghost/mocha/no-sibling-hooks": "off"
-    }
-}