Improve error output for rest functions.
Improve error output for rest functions.

rest_client.robot
  - OpenBMC Get Request:
    - Initialize OpenBMC should be called before logging the request to the
      console.  Otherwise, a failure in 'Initialize OpenBMC' looks like a
      failure to 'Get Request'.  I also made this change in 3 other keywords.
    - I added quiet parm on call to 'Initialize OpenBMC'.  I also made this
      change in "OpenBMC Post Request".
  - Initialize OpenBMC:
    - I added quiet parm.

Change-Id: I675c717d8554b12da8064e206c1b5cbc47fe6de0
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation