[worker] Import simplejson as json to make it easy to swap

2 jobs for 73_factorize_simplejson in 15 minutes and 33 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Build
passed #160324
docker-build
build_linux_36

00:12:22

63.0%
passed #160325
macosx
build_macosx_36

00:15:33

64.0%