bug 1461770: add pytest-forked to constraints
bug 1461770: add pytest-forked to constraints

jwhitlock/kuma,jwhitlock/kuma,Elchi3/kuma,SphinxKnight/kuma,SphinxKnight/kuma,jwhitlock/kuma,Elchi3/kuma,SphinxKnight/kuma,mozilla/kuma,Elchi3/kuma,mozilla/kuma,SphinxKnight/kuma,a2sheppy/kuma,mozilla/kuma,a2sheppy/kuma,SphinxKnight/kuma,escattone/kuma,Elchi3/kuma,escattone/kuma,escattone/kuma,jwhitlock/kuma,jwhitlock/kuma,mozilla/kuma,SphinxKnight/kuma,a2sheppy/kuma,a2sheppy/kuma,mozilla/kuma,Elchi3/kuma,a2sheppy/kuma