updated broken link to H5M (#111)
updated broken link to H5M (#111)

* updated broken link to H5M

I also found http://www.mcs.anl.gov/~fathom/moab-docs/h5mmain.html but I think it's older.

* http -> https in link to the home of H5M

as suggested by @nschloe

nschloe/meshio