updating changelog

Author: vsoch

CHANGELOG.md

@@ -17,6 +17,7 @@ The client here will eventually be released as "spython" (and eventually to
 singularity on pypi), and the versions here will coincide with these releases.
 
 ## [master](https://github.com/singularityhub/singularity-cli/tree/master)
+ - fixing bug in shell.py, cli should be client (0.0.40)
  - remove uri function should only right strip to support relative paths (0.0.39)
  - adjusting container build to use correct Github branch (vault/release-2.5)
  - adding support and documentation for container instances (0.0.38)