Move configuration to a configSchema

Move hte configuration to a key in the `package.json`, allowing Atom to be
able to read the settings without having to load up the package code.

Author: Arcanemagus

lib/main.js

@@ -1,20 +1,6 @@
 'use babel';
 
 export default {
-  config: {
-    rubyExecutablePath: {
-      type: 'string',
-      default: 'ruby',
-    },
-    ignoredExtensions: {
-      type: 'array',
-      default: ['erb', 'md'],
-      items: {
-        type: 'string',
-      },
-    },
-  },
-
   activate: () => {
     // We are now using steelbrain's package dependency package to install our
     //  dependencies.

package.json

@@ -6,12 +6,25 @@
   "repository": "https://github.com/AtomLinter/linter-ruby",
   "license": "MIT",
   "engines": {
-    "atom": ">0.180.0"
+    "atom": ">=1.4.0 <2.0.0"
   },
   "activationHooks": [
     "language-ruby:grammar-used",
     "language-ruby-on-rails:grammar-used"
   ],
+  "configSchema": {
+    "rubyExecutablePath": {
+      "type": "string",
+      "default": "ruby"
+    },
+    "ignoredExtensions": {
+      "type": "array",
+      "default": ["erb", "md"],
+      "items": {
+        "type": "string"
+      }
+    }
+  },
   "providedServices": {
     "linter": {
       "versions": {