Merge pull request #1658 from ferd/fix-install-readme

We no longer build the nightlies, just stables

README.md

@@ -81,7 +81,8 @@ $ ./rebar3 local install
 ```
 
 To keep it up to date after you've installed rebar3 this way you can use `rebar3 local upgrade` which
-fetches the latest nightly and extracts to the same place as above.
+fetches the latest stable release and extracts to the same place as above. A [nightly version can
+also be obtained](https://s3.amazonaws.com/rebar3-nightly/rebar3) if desired.
 
 Rebar3 may also be available on various OS-specific package managers such as
 FreeBSD Ports. Those are maintained by the community and Rebar3 maintainers