Update release documentation for contributors

We are not using Traveling Ruby since ea23f26.
Describe the new process!

Author: croaky

RELEASING.md

@@ -1,38 +1,20 @@
 Releasing
 =========
 
-Parity uses a set of `rake` tasks to create packages and bundles [traveling
-ruby][traveling_ruby] to simplify the dependency on Ruby.
-
-Generating packages
--------------------
-
-Packages can be generated for the following systems:
-
-* OSX `rake package:osx`
-* Linux x86 `rake package:linux:x86`
-* Linux x86_64 `rake package:linux:x86_64`
-
-You can generate all packages with `rake package:all`
-
-[traveling_ruby]: https://github.com/phusion/traveling-ruby
-
-The packages generated are tarballs of the following directory structure:
-
-    parity-package
-    ├── bin # shims
-    └── lib
-        ├── app # parity's bin and lib directories
-        └── ruby # traveling ruby for target system
-
-Releasing a new version
------------------------
-
 1. Update the version in `lib/parity/version.rb`
 1. Create a new tag based on the version number
-1. Generate packages
-1. Create a [release] for the latest tag and attach the packages
-1. Update the [homebrew formula] to point to the latest OSX package
+1. Create a GitHub [release] for the latest tag
+1. Update the [homebrew formula] to point to the latest GitHub release. Include
+   the path and the SHA.
+
+Development Releases
+====================
+
+Update the [development release] on the repository page, uploading a tarred,
+gzipped collection of files. The Homebrew formula does not require a SHA for a
+development build, and will always point to the file if the name remains
+consistent.
 
 [homebrew formula]: https://github.com/thoughtbot/homebrew-formulae/blob/master/Formula/parity.rb
 [release]: https://github.com/thoughtbot/parity/releases
+[development release]: https://github.com/thoughtbot/parity/releases/tag/development