[FIX]: email not being sent to post's author

[ayush00git]

• email is not being sent to post's author when the status updates or any admin comments.
  Most likely the [v2]: current design only sends email to stated users #97 needs to be implemented to solve this.

[ayush00git]

Updates needed -

• Post model -> Add an []string type field for storing People in conversation, keeping the post author's email and XEN type appended at the time the post is created.

[ayush00git]

Since the maximum number of people that could be in a post are just 5 (author, xen, ae, 2 jes), so we could just create a helper method - appendUnique an corollary to append() method of slice in go.