Redundant pulls in docker script and users in docker file

[cjones-teradici]

Hello.

I'd like to put up a pull request. I have it ready to go.
I just need push up a few lines of code to first fix fix redundant code in your script,
Then fix a portion of your docker file and finally demonstrate how this is supposed to be done.

Let me know how to proceed.

Kind Regards,
Chris