Fixes.

 * Fixed error handling in `PromptIndex`.
 * Simplified `Prompt`.

Change-Id: 3966956bac
Story-Id: 79415340
Review fixes.

Story-Id: 79415340
Change-Id: 3093da9f9d
Use more idiomatic Go mapping.

Change-Id: 8bf28c014f
Story-Id: 79415340
Merge branch 'develop' of github.com:salsita/SalsaFlow into develop
story start: Make the output more consistent

Make the output more consistent with the rest of the commands in case there is
an error. This is done by using errors.Error.Log instead of custom formatting.

Change-Id: f73f5ec671
story start: Use ReadableId to find story branch

Change-Id: 7afe4e0995
wip

Change-Id: 9448896101
Story-Id: SF-6