Calculate percentage of FW tests written

BUG=b:147815722
TEST=1. sudo emerge sys-firmware/fw-engprod-tools
     2. fw_e2e_coverage_summarizer

Change-Id: I78e9b4967d40755af6312afbdb47b03f9ca52234
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/2041705
Tested-by: Greg Edelston <gredelston@google.com>
Reviewed-by: Kevin Shelton <kmshelton@chromium.org>
Commit-Queue: Greg Edelston <gredelston@google.com>
2 files changed