Update changelog for the 0.7.0 release. (Yes, this should have been committed earlier today.)

changelog.md

@@ -1,7 +1,5 @@
 # Changes in version 0.7.0
 
-**Version 0.7.0 has not been released.  This changelog is a work in progress.**
-
 This is a stable bugfix and feature release.  Major new features and changes include:
 
 - Add `ZSH_HIGHLIGHT_DIRS_BLACKLIST` to disable "path" and "path prefix"
@@ -71,13 +69,6 @@ Known issues include:
   for examples and workarounds.
   [#677]
 
-- Use of a simple parameter expansion (`${foo}` with nothing but a parameter
-  name inside the braces) in command position, when the value of the parameter
-  looks like an assignment (such as after `foo='bar=$(ls)'`), may result in
-  incorrect highlighting and "BUG" messages.  As a workaround, the expansion
-  may be nested (`${${foo}}`).
-  [#670]
-
 
 # Changes in version 0.6.0