tree a8d799701bec4089e8dd6565d39c2dd04f55e51d
parent 93e6a0370085b0488b8542a66f4adcbf11f4a390
author Brant Knudson <bknudson@us.ibm.com> 1476381109 -0500
committer Brant Knudson <bknudson@us.ibm.com> 1476385943 -0500

Improve error reporting when workspace not registered

When the user ran

 tempest run --workspace <whatever>

and the workspace wasn't in .tempest/workspace.yaml the eror message
reported was

 CRITICAL tempest [-] TypeError: coercing to Unicode: need string or buffer, NoneType found.

Rather than report this error, a message is printed saying that the
workspace isn't registered.

Change-Id: Ic539ee2fab83401904fcaec2c3fbf1cd41e4a6e3