upgrade dependency to a version that supports node@6

Author: mikesamuel

package.json

@@ -19,7 +19,7 @@
   ],
   "repository": "mysqljs/sqlstring",
   "dependencies": {
-    "template-tag-common": "3.0.1"
+    "template-tag-common": "3.0.2"
   },
   "devDependencies": {
     "beautify-benchmark": "0.2.4",

test/unit/es6/canary.js

@@ -2,10 +2,6 @@
 // older browsers.
 `I load on ES6`;
 
-if (!Object.getOwnPropertyDescriptors) {
-  throw new Error('Incomplete property descriptor support');
-}
-
 module.exports = function usesRestArgs (...args) {
   return args;
 };