Venue Configuration with invitation templates

[melisabok]

• Initial commit:

1. Create template for the venue group
2. Add process function to create meta invitation and add the venue group to the venues and active_venues group

Pending issues:

• Allow web field in group invitations
• Create template for meta invitations that include the date process function scripts. API error trying to set edit=true
• Decide if we need to create the subgroups or not. At least host is needed for the home page.
• Set domain value for group template invitations.