installer misses dependencies

[grubernd <lists mehrzweckraum com>]

hi..

i just installed California 0.4.0 on xubuntu 16.04 and after some 
cursing and digging around i found the following note on gitgub:

"California uses EDS (Evolution Data Server) as the back-end for 
managing your calendars."

well, it might be a reasonable idea to add that to the dependencies of 
the package. doing a `sudo apt install evolution-data-server` isn't 
really all that intuitive.


cheers,
grubernd