Replace gh-release with curl (#1896)
Replace gh-release with curl (#1896)

* Replace gh-release with curl

This fix tries to address the issue raised in 1895 where
gh-release is deprecated.

As GitHub provides API that could be accessed easily,
and gh-release itself is just a wrapper to the API,
this fix replaces gh-release with the direct interaction
with GitHub API, so that it could be maintained by coredns
team.

This fix fixes 1895.

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

* Added `-o /dev/null`

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

johnbelamaric/coredns,jremond/coredns,jremond/coredns,miekg/coredns,johnbelamaric/coredns,chrisohaver/coredns,coredns/coredns,ii/coredns,miekg/coredns,yongtang/coredns,ii/coredns