Fix for conda-forge package (#930)

* Added meta.yaml for conda packaging.

* Ready to merge with master branch.

* Succeeded in creating a conda package.

* Modified MANIFEST.in to make the conda-forge package.

In order to fix this I followed the issue astropy/astropy-helpers#221 and the MANIFEST.in from astroquery.

* Deleted meta.yaml because it's not necessary anymore

MANIFEST.in

@@ -19,6 +19,7 @@ prune docs/_build
 prune docs/api
 
 recursive-include astropy_helpers *
+recursive-include astropy_helpers/astropy_helpers.egg-info *
 exclude astropy_helpers/.git
 exclude astropy_helpers/.gitignore