Update the CHANGELOG.md with all changes since last release

Co-authored-by: George Blue <gblue@pivotal.io>

CHANGELOG.md

@@ -1,5 +1,16 @@
 ## HEAD
 
+### Features
+- Make string pretty diff user configurable (#273) [eb112ce, 649b44d]
+
+### Fixes
+- Use httputil.DumpRequest to pretty-print unhandled requests (#278) [a4ff0fc, b7d1a52]
+- fix typo floa32 > float32 (#272) [041ae3b, 6e33911]
+- Fix link to documentation on adding your own matchers (#270) [bb2c830, fcebc62]
+- Use setters and getters to avoid race condition (#262) [13057c3, a9c79f1]
+- Avoid sending a signal if the process is not alive (#259) [b8043e5, 4fc1762]
+- Improve message from AssignableToTypeOf when expected value is nil (#281) [9c1fb20]
+
 ## 1.3.0
 
 Improvements:

RELEASING.md

@@ -1,6 +1,12 @@
 A Gomega release is a tagged sha and a GitHub release.  To cut a release:
 
-1. Ensure CHANGELOG.md is uptodate.
+1. Ensure CHANGELOG.md is up to date.
+  - Use `git log --pretty=format:'- %s [%h]' HEAD...vX.X.X` to list all the commits since the last release
+  - Categorize the changes into
+    - Breaking Changes (requires a major version)
+    - New Features (minor version)
+    - Fixes (fix version)
+    - Maintenance (which in general should not be mentioned in `CHANGELOG.md` as they have no user impact)
 2. Update GOMEGA_VERSION in `gomega_dsl.go`
 3. Push a commit with the version number as the commit message (e.g. `v1.3.0`)
-4. Create a new [GitHub release](https://help.github.com/articles/creating-releases/) with the version number as the tag  (e.g. `v1.3.0`).  List the key changes in the release notes.
+4. Create a new [GitHub release](https://help.github.com/articles/creating-releases/) with the version number as the tag  (e.g. `v1.3.0`).  List the key changes in the release notes.