Group with spaces in name, no error messages in UI

[jcsrb]

I checked out the master branch and started bandiera using docker as described in the README.
When first creating a group I tried a group name that contained spaces and pressed submit. Submitting the form didn't show an error but redirected me back to the form.

it is ok if spaces in names are not supported but it took me a bit to figure out as there was no error message