Remove babel-polyfill

Should be no need for it if we're using transform-runtime (and
we definitely don't need it twice...)

package.json

@@ -36,7 +36,6 @@
     "test:multi": "karma start"
   },
   "dependencies": {
-    "babel-polyfill": "^6.5.0",
     "babel-runtime": "^6.11.6",
     "browser-request": "^0.3.3",
     "classnames": "^2.1.2",
@@ -67,7 +66,6 @@
     "babel-eslint": "^6.1.0",
     "babel-loader": "^6.2.5",
     "babel-plugin-transform-runtime": "^6.15.0",
-    "babel-polyfill": "^6.5.0",
     "babel-preset-es2015": "^6.16.0",
     "babel-preset-es2016": "^6.16.0",
     "babel-preset-es2017": "^6.16.0",

src/vector/index.js

@@ -16,10 +16,6 @@ limitations under the License.
 
 'use strict';
 
-// for ES6 stuff like startsWith() that Safari doesn't handle
-// and babel doesn't do by default
-require('babel-polyfill');
-
 // CSS requires: just putting them here for now as CSS is going to be
 // refactored soon anyway
 require('../../vector/components.css');