Don't use docker-machine for tests

2 jobs for docker in 1 minute and 30 seconds (queued for 9 seconds)
Status Job ID Name Coverage
  Test
failed #21995
lidiap2015
py27-linux

00:00:35

failed #21996
beat-macosx
py27-macosx

00:00:55

 
Name Stage Failure
failed
py27-macosx Test There is an unknown failure, please try again
beat/core/toolchain.py      210     69    67%   55, 151, 168, 178, 190, 199, 238, 253-254, 259-260, 266, 273, 284-285, 385-463, 481, 488-493, 499-505, 511-514, 552-554
beat/core/utils.py 127 30 76% 45, 61, 67-69, 113-118, 144-146, 170-172, 216-217, 223, 228-229, 267, 284, 290, 294-296, 309-311
-------------------------------------------------------
TOTAL 3209 1235 62%
----------------------------------------------------------------------
Ran 327 tests in 10.652s

FAILED (errors=2)
ERROR: Build failed: exit status 1
failed
py27-linux Test There is an unknown failure, please try again
mr.developer: Permission denied (publickey).
mr.developer: fatal: Could not read from remote repository.
mr.developer:
mr.developer: Please make sure you have the correct access rights
mr.developer: and the repository exists.
mr.developer:
mr.developer: Cloned 'cpulimit' with git.
mr.developer: There have been errors, see messages above.
ERROR: Build failed: exit status 1