parses out semver of firmware builds
Adds -l argument for run to select what logs to display.
Merge pull request #93 from tessel/tcr-listen

Adds -l argument for run to select what logs to display.
adds null check for builds and skips 'current' firmware
changing to not use builds namespace collision
adding warning message
v0.3.7
Merge pull request #91 from tessel/jh-semver

parses out semver of firmware builds
merging in --listen option