removed opbeat from base settings. changed email settings over to use environ.get so that if they aren't defined the site can still be loaded.
removed opbeat from base settings. changed email settings over to use environ.get so that if they aren't defined the site can still be loaded.

poldracklab/open_fmri,poldracklab/open_fmri,poldracklab/open_fmri,poldracklab/open_fmri