Add changelog for #517

Author: Michael Snoyman

ChangeLog.md

@@ -2,6 +2,7 @@
 
 * Set the `HASKELL_DIST_DIR` environment variable [#524](https://github.com/commercialhaskell/stack/pull/524)
 * Track build status of tests and benchmarks [#525](https://github.com/commercialhaskell/stack/issues/525)
+* `--no-run-tests` [#517](https://github.com/commercialhaskell/stack/pull/517)
 
 ## 0.1.2.0