Remove transform-runtime

We use instance methods (or at least, draft.js does) so we need
babel-polyfill instead.

.babelrc

@@ -1,4 +1,3 @@
 {
-  "presets": ["react", "es2015", "es2016", "es2017", "stage-2"],
-  "plugins": ["transform-runtime"]
+  "presets": ["react", "es2015", "es2016", "es2017", "stage-2"]
 }

package.json

@@ -36,6 +36,7 @@
     "test:multi": "karma start"
   },
   "dependencies": {
+    "babel-polyfill": "^6.5.0",
     "babel-runtime": "^6.11.6",
     "browser-request": "^0.3.3",
     "classnames": "^2.1.2",
@@ -66,6 +67,7 @@
     "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

@@ -16,6 +16,15 @@ limitations under the License.
 
 'use strict';
 
+// for ES6 stuff like startsWith() that Safari doesn't handle
+// and babel doesn't do by default
+// Note we use this, not the babel transform-runtime plugin
+// since transform-runtime does not cover instance methods
+// such as "foobar".includes("foo") which bits of our library
+// code use.
+// https://babeljs.io/docs/plugins/transform-runtime/
+require('babel-polyfill');
+
 // CSS requires: just putting them here for now as CSS is going to be
 // refactored soon anyway
 require('../../vector/components.css');