updated GLM imports

[TheChymera]

Updated the import, as suggested by this warning I am getting:

/usr/lib64/python2.7/site-packages/nipy/labs/glm/glm.py:9: FutureWarning: Module nipy.labs.utils.routines deprecated, will be removed
  from ..utils import mahalanobis
/usr/lib64/python2.7/site-packages/nipype/interfaces/nipy/model.py:18: FutureWarning: Module nipy.labs.glm deprecated, will be removed. Please use nipy.modalities.fmri.glm instead.
  import nipy.labs.glm.glm as GLM

Tested the update with real data.

[coveralls]

Coverage increased (+0.03%) to 72.239% when pulling 85aab7a on TheChymera:importfix into a26ef19 on nipy:master.

[TheChymera]

@satra looking good?