Fixes #325 - add persistent sub-man settings in bootstrap.py

[snagoor]

Introduced new flags in bootstrap.py as below for persistent rhsm proxy settings

 --rhsm-proxy-name=RHSM_PROXY_NAME
                        Proxy Server Name which shall be passed to
                        subscription-manager
  --rhsm-proxy-port=RHSM_PROXY_PORT
                        Proxy Server Port which shall be passed to
                        subscription-manager
  --rhsm-proxy-user=RHSM_PROXY_USER
                        Proxy Server Username which shall be passed to
                        subscription-manager
  --rhsm-proxy-password=RHSM_PROXY_PASSWORD
                        Proxy Server Password which shall be passed to
                        subscription-manager
  --preserve-rhsm-proxy-settings
                        Preserve proxy settings in /etc/rhsm/rhsm.conf when
                        RHSM Proxy Settings are used

[sideangleside]

Is this not what the --preserve-rhsm-proxy option does today? (See #283)

[snagoor]

Is this not what the --preserve-rhsm-proxy option does today? (See #283)

@sideangleside thank you for the review. You are correct #283 does the job only when the user manually fills-in the proxy entries in rhsm.conf file and before executing the bootstrap.py script.

This is not ideal in a situation where an end user want to automate the registration of hosts, first they have to fill in all the proxy details in rhsm.conf on hosts and then execute the bootstrap script with --preserve-rhsm-proxy flag. So, having the necessary flags exposed as options would help them achieve both these things in one-go.

Just want to improve the user experience here.