1.7.0-beta.2

Fixed: White block at bottom of conversation panel in iOS theme
(#2144 and #2153)

Fixed: Would attempt to rotate signed prekey every five seconds,
forever, after app discovers it is unlinked
(1c6d91b59c)

Dev:
  - Introduce IndexedDB index on `messages` store tracking
    `schemaVersion` (#2128)
  - Preparation for encrypted backups
    (cea42bde7d)
  - Updates to structure of exported data - messages.zip, flat list of
    attachments (6d8f4b7b6e)

package.json

@@ -3,7 +3,7 @@
   "productName": "Signal",
   "description": "Private messaging from your desktop",
   "repository": "https://github.com/signalapp/Signal-Desktop.git",
-  "version": "1.7.0-beta.1",
+  "version": "1.7.0-beta.2",
   "license": "GPL-3.0",
   "author": {
     "name": "Open Whisper Systems",