Add Prettier configuration (#574)

tslint.json

@@ -40,7 +40,6 @@
     "object-literal-shorthand": [ true, "never" ],
     "ordered-imports": true,
     "prefer-for-of": false,
-    "quotemark": [ true, "single" ],
     "whitespace": [
       true,
       "check-branch",
@@ -52,14 +51,7 @@
       "check-type"
     ],
     "max-classes-per-file": false,
-    "arrow-parens": [
-      true,
-      "ban-single-arg-parens"
-    ],
-    "semicolon": [
-      true,
-      "always"
-    ],
+    "arrow-parens": [true],
     "trailing-comma": [
       true,
       {