Finding areas that are untested and need love (#4131)

* Makes InstallationRouter like others

* Adds testing for Range file requests

- Fixes issue with small requests (0-2)

* Revert "Makes InstallationRouter like others"

This reverts commit e2d2a16ebf2757db6138c7b5b33c97c56c69ead6.

* Better handling of errors in FilesRouter

* Fix incorrectness in range requests

* Better/simpler logic

* Only on mongo at it requires Gridstore

* Open file streaming to all adapters supporting it

* Improves coverage of parsers

* Ensures depreciation warning is effective

* Removes unused function

* de-duplicate logic

* Removes necessity of overriding req.params.className on subclasses routers

* Use babel-preset-env to ensure min-version compatible code

* removes dead code

* Leverage indexes in order to infer which field is duplicated upon signup

- A note mentioned that it would be possible to leverage using the indexes on username/email to infer which is duplicated

* Small nit

* Better template to match column name

* Restores original implementation for safety

* nits

src/Push/PushWorker.js

@@ -10,8 +10,6 @@ import * as utils             from './utils';
 import { ParseMessageQueue }  from '../ParseMessageQueue';
 import { PushQueue }          from './PushQueue';
 
-const UNSUPPORTED_BADGE_KEY = "unsupported";
-
 function groupByBadge(installations) {
   return installations.reduce((map, installation) => {
     const badge = installation.badge + '';
@@ -93,11 +91,7 @@ export class PushWorker {
     // Map the on the badges count and return the send result
     const promises = Object.keys(badgeInstallationsMap).map((badge) => {
       const payload = deepcopy(body);
-      if (badge == UNSUPPORTED_BADGE_KEY) {
-        delete payload.data.badge;
-      } else {
-        payload.data.badge = parseInt(badge);
-      }
+      payload.data.badge = parseInt(badge);
       const installations = badgeInstallationsMap[badge];
       return this.sendToAdapter(payload, installations, pushStatus, config);
     });