Pinned Travis Python version in conda env to 3.4.3-2
Pinned Travis Python version in conda env to 3.4.3-2

Between Python versions 3.4.3-2 and 3.4.4 a backwards incompatible
change to pickling was added, old pickles can't be loaded.
Eventually we'll want to update the reference data to 3.4.4 or 3.5

vascotenner/holoviews,vascotenner/holoviews,basnijholt/holoviews,ioam/holoviews,vascotenner/holoviews,basnijholt/holoviews,ioam/holoviews,basnijholt/holoviews,ioam/holoviews