grim/hgkeeper

dc46af0b583b
Spit out a warning if we find a duplicated key.

We're going to continue the existing behavior of overwriting the keys to not
break potential set ups for the time being.

Fixes HGKEEPER-22
# Create The `hg` User
You can name this user whatever you like, but for the sake of simplicity, we
will just be using `hg` here. We are also going to create an `hg` group to keep
to make sure file permissions remain tight. For most Linux/BSD distributions,
you can create the `hg` user and group with the following commands:
```
sudo groupadd --system hg
sudo useradd --home-dir /var/lib/hg --create-home --system --gid hg
```
This is the username that you will need to specify when connecting to the
OpenSSH Server and is how we will configure the server to tell it how to serve
Mercurial repositories.