Apache likes to be not just told how to handle test.icalshare.com, but asked to handle it. If you don't ask it to handle it before telling it how, it'll complain on restart and might even mis-handle some sites.
First, scroll just above the VirtualHost directives and add a NameVirtualHost directive:
Then restart Apache: sudo apachectl restart
You can also restart apache via System Preferences, but by doing it at the command line, you'll get to immeadiately see any errors that stopped Apache from starting.