Updating keys manually before update

Author: Hi-Fi

.travis/setup_xvfb.sh

@@ -1,5 +1,6 @@
 #!/bin/bash
 
+sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 762E3157
 sudo apt-get -qq update
 sudo apt-get install -y dbus-x11
 export DISPLAY=:99.0