Consistent treatment of labels with leading (trailing) spaces

[jbusecke]

I just discovered that when you specify recipe labels with leading spaces (run: some_recipe_id), the recipe will get picked up by the action (it tries to run it), but will fail due to the constucted jobname still containing spaces (which dataflow hates).

We should make this behavior consistent by doing one of the below:

• Error out earlier in the action (with helpful error message) if the label based id contains spaces
• Or remove spaces automatically as part of the name generation.

I guess if we are implementing one or the other we want to take care of trailing spaces too?