Missing directories in fpa about fieldprime_server

[taerwin]

@robsyme sslStuff will need to be created outside of docker as it contains the ssl certificate files (server.crt, server.key) required by apache/flask if you want to run fieldprime in a production mode. I will add some documentation about this.

fp_app_api is no longer used and should be removed. I will add a fix.

[alexwhan]

@taerwin could you have a look at this?

[robsyme]

I thought that might be the case for sslStuff, but it's good to know I've not done something dumb to be missing fp_app_api.

[taerwin]

I have cleaned up the Dockerfile(s) and added an empty sslCerts directory where ssl certificates will need to be placed to use https.

[robsyme]

Thanks taerwin.