partially fixes #156 -- but still needs work, doesnt currently load velocities properly
added Velocities to map to vel array
added Potential -> phi mapping for gadgethdf
Merge branch 'master' into gadget_hdf_fix
made a bridge tutorial out of the bridge docstring
changed docs_update.sh to remove testdata links
included stream mode option to velocity_image that was added in #169 and updated the tutorial example
fixed width unit handling in pynbody.stars.render and added example to pictures tutorial
changed profile tutorial, updated some other things
Fixes #170
Merge pull request #157 from pynbody/gadget_hdf_fix

fix for #156 -- support loading DM only files for gadgethdf
fixes #148
Merge branch 'master' of github.com:pynbody/pynbody
trying to get travis build
fetch testdata first?
dont need matplotlib for nosetests
scipy wont build on travis CI
pruning the requirements further
bad filename
trying conda for scipy/numpy in travis