gridDataFormats conda build

[orbeckst]

Make package available in anaconda so that it can be pulled by mdanalysis. See MDAnalysis/mdanalysis#608 for details.

[kain88-de]

It should be possible to use the stuff from MDAnalysis/mdanalysis#571 to build and push GridDataFormats to conda

[orbeckst]

@richardjgowers I made you the owner because it needs to be handled together with MDAnalysis/mdanalysis#608.