update changelog - allow cachedir override

CHANGELOG.md

@@ -30,6 +30,8 @@ Improving performance when updating dependencies with `-update`. (#1175)
 (#1135)
 * gps: Add SourceURLsForPath() to SourceManager. (#1166)
 * gps: Include output in error. (#1180)
+* Allow override of cache directory location using environment variable
+`DEPCACHEDIR`. (#1234)
 
 WIP:
 
@@ -50,7 +52,7 @@ importer would drop the imported version of a project (#1100)
 * Import analyzer now always uses the same name, fixing the lock mismatch
 immediately after dep init issue (#1099)
 * Add support for importing from [govend](https://github.com/govend/govend)
-(#1040) and [LK4D4/vndr](https://github.com/LK4D4/vndr) (#978) based projects 
+(#1040) and [LK4D4/vndr](https://github.com/LK4D4/vndr) (#978) based projects
 * gps: gps no longer assumes that every git repo has a HEAD (#1053)
 * `os.Chmod` failures on Windows due to long path length has been fixed (#925)
 * Add `version` command (#996)