Updating outdated dependencies and switching to yarn

Author: raphaelokon

package.json

@@ -15,23 +15,23 @@
     "bs-html-injector": "3.0.3",
     "chalk": "1.1.3",
     "commander": "2.9.0",
-    "execa": "0.6.1",
-    "fs-promise": "2.0.0",
+    "execa": "0.6.3",
+    "fs-promise": "2.0.2",
     "glob": "7.1.1",
     "has-yarn": "1.0.0",
     "inquirer": "2.0.0",
     "lodash": "4.17.4",
-    "ora": "1.1.0",
+    "ora": "1.2.0",
     "path-exists": "3.0.0",
-    "patternlab-node": "2.8.0",
+    "patternlab-node": "2.9.2",
     "sanitize-filename": "1.6.1"
   },
   "devDependencies": {
     "edition-node": "0.0.4",
-    "eslint": "3.17.1",
+    "eslint": "3.19.0",
     "proxyquire": "1.7.11",
     "starterkit-mustache-base": "3.0.1",
-    "tap": "10.3.0"
+    "tap": "10.3.2"
   },
   "files": [
     "bin"
@@ -45,7 +45,7 @@
   "scripts": {
     "lint": "eslint ./{bin,test}",
     "test": "tap './test/*.test.js' --reporter spec --timeout=120",
-    "pretest": "npm run lint && npm install --only=dev"
+    "pretest": "yarn run lint && yarn install"
   },
   "repository": {
     "type": "git",