Leave
/api/v2/group/leave
Post
groups
jwt
Purpose
To allow a user to leave a group that he/she is already a member of.
Body Content [input]
{
    uid: string,
    groupID: string
}
Returns if valid [output]
{
    message: string,
    error: 0
}
What the API does
- Finds the 
groupbeing referenced by thegroupIDpassed [404]. - Ensures that 
uidcorresponds to a record in themembersfield with astatusofaccepted[403]. - Removes the record in the 
membersfield corresponding touidfrom thegroup.