upgrade prettier; use .prettierrc

.prettierrc

@@ -0,0 +1,3 @@
+useTabs: true
+singleQuote: true
+trailingComma: es5

package.json

@@ -21,7 +21,7 @@
     "dev": "node src/shared/_build.js && rollup -c -w",
     "pretest": "npm run build",
     "prepublishOnly": "npm run lint && npm test",
-    "prettier": "prettier --use-tabs --single-quote --trailing-comma es5 --write \"src/**/*.ts\""
+    "prettier": "prettier --write \"src/**/*.ts\""
   },
   "repository": {
     "type": "git",
@@ -59,7 +59,7 @@
     "nightmare": "^2.10.0",
     "node-resolve": "^1.3.3",
     "nyc": "^11.1.0",
-    "prettier": "^1.4.1",
+    "prettier": "^1.7.0",
     "rollup": "^0.48.2",
     "rollup-plugin-buble": "^0.15.0",
     "rollup-plugin-commonjs": "^8.0.2",

yarn.lock

@@ -2310,8 +2310,8 @@ preserve@^0.2.0:
   resolved "https://registry.yarnpkg.com/preserve/-/preserve-0.2.0.tgz#815ed1f6ebc65926f865b310c0713bcb3315ce4b"
 
 prettier@^1.4.1:
-  version "1.5.3"
+  version "1.7.0"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.5.3.tgz#59dadc683345ec6b88f88b94ed4ae7e1da394bfe"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.7.0.tgz#47481588f41f7c90f63938feb202ac82554e7150"
 
 pretty-bytes@^1.0.2:
   version "1.0.4"