Add libdbus-1-3 dependency for Electron 3 builds of Atom

Description of the Change

Latest Teletype master builds on Travis CI against Atom Dev are failing with a renderer crash. One obvious starting point is this error that gets written out in the dev build log:

/home/travis/atom/usr/share/atom-dev/atom: /lib/x86_64-linux-gnu/libdbus-1.so.3: no version information available (required by /home/travis/atom/usr/share/atom-dev/atom)

This change adds libdbus-1-3 to the apt-get install call to ensure that this dependency exists on the CI machine.

Alternate Designs

None at the moment, let's see if this fixes the issue.

Benefits

Passing dev builds on master.

Possible Drawbacks

None.

Verification Process

[x] Verified that no renderer process crash occurs locally on my Linux dev machine
[ ] Green CI build after adding the new dependency

Applicable Issues