Added coverage CI with coveralls to travis.yml
Added coverage CI with coveralls to travis.yml

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