tracer: update to newest version of CLS
http: Parse queue time header value as floating point

Some queue time headers come in floating point seconds units. The
current usage of parseInt() truncates the queue start time value to
seconds, which leads to some random bias to the queue time between 0 and
0.999 seconds.

The tests were refactored to:
  * test values in small number of ms rather than 1000+ ms so the above
    can actually be tested
  * print out the expected range and actual value for queue time
index.js: invalid app_names based on regular expressions will log and not start up agent
docs: updated for new version
release: published 1.9.1