Add grep_token_logs.py
Add grep_token_logs.py

Helpful for tracing when a particular bot was using a particular token

Bug: skia:
Change-Id: I2d54e09233450ab48b4de5c0226e7da081fb696f
Reviewed-on: https://skia-review.googlesource.com/113708
Commit-Queue: Eric Boren <0e499112533c8544f0505ea0d08394fb5ad7d8fa@google.com>
Reviewed-by: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot