Added babel-preset-es2015-loose to support IE 10 and es6-promise polyfill

Added babel-preset-es2015-loose
(https://www.npmjs.com/package/babel-preset-es2015-loose) to support
classes and super in IE 10

Might need transform-proto-to-assign too
https://phabricator.babeljs.io/T3041, but this works for now

.babelrc

@@ -1,4 +1,4 @@
 {
-  "presets": ["es2015"],
-  "plugins": ["transform-object-assign"]
+  "presets": ["es2015-loose"],
+  "plugins": ["transform-object-assign", "es6-promise"]
 }

package.json

@@ -55,21 +55,25 @@
     "babel-core": "6.7.4",
     "babel-eslint": "6.0.2",
     "babel-loader": "6.2.4",
+    "babel-plugin-es6-promise": "1.0.0",
     "babel-plugin-transform-object-assign": "6.5.0",
+    "babel-plugin-transform-proto-to-assign": "6.8.0",
     "babel-polyfill": "6.7.4",
-    "babel-preset-es2015": "^6.0.0",
+    "babel-preset-es2015": "6.6.0",
+    "babel-preset-es2015-loose": "7.0.0",
     "babel-register": "6.7.2",
     "babelify": "7.2.0",
     "browser-sync": "2.10.0",
     "browserify": "12.0.1",
     "chalk": "1.1.1",
     "disc": "1.3.2",
+    "es6-promise": "3.1.2",
     "eslint": "2.7.0",
     "eslint-config-standard": "5.1.0",
     "eslint-plugin-promise": "1.1.0",
     "eslint-plugin-standard": "1.3.2",
     "fakefile": "0.0.5",
-    "isomorphic-fetch": "^2.2.1",
+    "isomorphic-fetch": "2.2.1",
     "multi-glob": "1.0.1",
     "nock": "^8.0.0",
     "node-fetch": "^1.5.0",
@@ -77,7 +81,7 @@
     "node-sass": "3.4.2",
     "nodemon": "1.8.1",
     "parallelshell": "2.0.0",
-    "selenium-webdriver": "^2.52.0",
+    "selenium-webdriver": "2.52.0",
     "tap-spec": "^4.1.1",
     "tape": "4.4.0",
     "uppy-server": "0.0.3",
@@ -86,7 +90,7 @@
   "dependencies": {
     "drag-drop": "2.11.0",
     "tus-js-client": "1.1.3",
-    "whatwg-fetch": "^1.0.0",
+    "whatwg-fetch": "1.0.0",
     "yo-yo": "1.1.1"
   }
 }