Follow-up from https://gerrit.wikimedia.org/r/#/c/performance/navtiming/+/478577:
A new warning was introduced in flake8 and because we don't specify a version, it caused master to break without a change. We should pin dependencies so that upgrades are explicit, and tests are deterministic and identical between local development and Jenkins.
Repositories to check:
- performance/navtiming
- performance/coal
- performance/arc-lamp