Use a monospace font

Monospace fonts are the most readable family of text for code, logs, and
development-related snippets.

Bug: PASTE-17

Change-Id: I4c341da6e4785880b45bea4b366f20a39ed7d2c7
Bump version to 5.1.3

Change-Id: I9d42152ef1421ab63c693d81735d1d8b469e1e65