retry a few times (with exponential backoff) if service responds with a 503
unnecessary change to test util
from code review
changed method in timeutils to throw exception to signal retry
add retry exception
throw new exception when user request limit has been exceeded
Merge pull request #1291 from jay-hodgson/SWC-1420

Swc-1420: retry a few times (with exponential backoff) if service responds with 503