error handling for 'kanban state not associated with kanban stage
Update README.md
only showed valid kanban board in setting, now show all to make re-enabled possible
Update README.md
Fixes issue #45

Prevent exception if the project associated with the Kanban no longer
exists.
Possibly fixes issue #17

Probably fixes issue #17 although could do with testing on more than my
single development system.
Merge remote-tracking branch 'upstream/master'
Merge pull request #48 from prmartinuk/master

Fixes #45 and #17