Implement e2e export

package.json

@@ -47,10 +47,12 @@
     "browser-encrypt-attachment": "^0.3.0",
     "browser-request": "^0.3.3",
     "classnames": "^2.1.2",
+    "commonmark": "^0.27.0",
     "draft-js": "^0.8.1",
     "draft-js-export-html": "^0.5.0",
     "draft-js-export-markdown": "^0.2.0",
     "emojione": "2.2.3",
+    "file-saver": "^1.3.3",
     "filesize": "^3.1.2",
     "flux": "^2.0.3",
     "fuse.js": "^2.2.0",
@@ -59,7 +61,6 @@
     "isomorphic-fetch": "^2.2.1",
     "linkifyjs": "^2.1.3",
     "lodash": "^4.13.1",
-    "commonmark": "^0.27.0",
     "matrix-js-sdk": "matrix-org/matrix-js-sdk#develop",
     "optimist": "^0.6.1",
     "q": "^1.4.1",