Bump version and document changes

changelog

+Changes in version 0.12.0.1
+
+ * Make sure `length` can be inlined
+ * Include modules that test-suites depend on in other-modules
+
 Changes in version 0.12.0.0
 
  * Documentation fixes/additions

vector.cabal

 Name:           vector
-Version:        0.12.0.0
+Version:        0.12.0.1
 -- don't forget to update the changelog file!
 License:        BSD3
 License-File:   LICENSE