Small tweaks for pcc script

* Strip leading whitespace from lines, to make the output uniform.
* Grep the output for failures before declaring the compiler run to be
  successful, since Puppet's exit codes are not always meaningful.
  See <https://projects.puppetlabs.com/issues/17017>.
* Throttle requests by sleeping for 1 second in the poll loop.

Change-Id: I635e2d613ae879ceaa06571b06ad5871940672e2
Merge "Small tweaks for pcc script" into production