createGroupAsync 
suspend fun createGroupAsync(groupName: String, members: Array<String>, admins: Array<String>, privateKeys: PreGeneratedKeys? = null): String
Create a group, and returns the created group's ID. admins must also be members. admins must include yourself.
Return 
The ID of the created group.
Parameters 
| groupName | A name for the group. This is metadata, useful on the Seald Dashboard for recognizing this user. | 
| members | The Seald IDs of the members to add to the group. Must include yourself. | 
| admins | The Seald IDs of the members to also add as group admins. Must include yourself. | 
| privateKeys | Optional. Pre-generated private keys, returned by a call to generatePrivateKeys or generatePrivateKeysAsync. | 
Throws 
| SealdException |