* Add benchmark to CI
The page load benchmark for Chrome is now run during CI, and the
results are collected and summarized in the `metamaskbot` comment.
Closes#6881
* Double default number of samples
The number of default samples was changed from 10 to 20. The results
from 10 samples would show statistically significant changes in page
load times between builds, so weren't a sufficiently useful metric.
Mark Stacey
550fba2466