Use NumPy 1.11 with Python 3.4 (#3482)
Use NumPy 1.11 with Python 3.4 (#3482)

Appears that Pandas 0.19 and NumPy 1.12 conflict due to the Conda
package for Pandas' version constraints (particularly for Python 3.4).
So try downgrading the NumPy version used in this CI matrix to fix this
issue.
dask/dask,ContinuumIO/dask,jcrist/dask,dask/dask,jakirkham/dask,jakirkham/dask,ContinuumIO/dask,mrocklin/dask,mrocklin/dask,jcrist/dask,blaze/dask,blaze/dask