Friendlier build error

Hide the backtrace and show a comprehensible message.

Closes #160.
Stop 'fig up' when a container exits

Closes #1 ヽ(*・ω・)ﾉ
Updates the mac build script so it wont fail when the venv folder does not exist.
Merge pull request #173 from colinmccune/master

Fixes the mac build script so it wont fail when the venv folder doesn't exist
Merge pull request #165 from orchardup/number-one

Stop 'fig up' when a container exits
Merge pull request #164 from orchardup/friendlier-build-error

Friendlier build error