TST: Increasing testing on life.

Trying to sort out buildbot failures:

http://nipy.bic.berkeley.edu/builders/dipy-py2.7-osx-10.7/builds/204/steps/shell_6/logs/stdio

http://nipy.bic.berkeley.edu/builders/dipy-py2.6-32/builds/442/steps/shell_5/logs/stdio
Merge pull request #515 from arokem/life-bots

TST: Increasing testing on life.