Robo 3T 1.2 - Beta

This beta is a test only release (not an official release).
Main purpose of this beta is to test the following problems: crash on sierra, ssh error, Ubuntu failed start.

Improvements & Fixes:
  - Qt version upgraded from Qt 5.7.0 to Qt 5.9.3
  - Fix for "Cannot load list of indexes #1454"
  - Improvements for Robo 3T is crashing constantly on High Sierra #1412
  - PR: Improved query time formatting (#1358) #1455
  - Fix for "Robo 3T is not buildable on latest MacOS vesion High Sierra"
  - Fix attempt for "Error: Resources temporarily unavailable. Error when starting up SSH session: -8 #1426"
  - Fix for "robo3t 1.1 failed to start on Ubuntu 17.04 #1385"