Add app fixture to fix TestPaymentPortal.test_with_app_slug
Merge pull request #1988 from muffinresearch/fix-borken-test-app-slug

Add app fixture to fix TestPaymentPortal.test_with_app_slug
Removed apps/compat/ (bug 999120)
Removed apps/perf/ and associated stuff (bug 999153)
Removed apps/sharing/ (bug 999154)
Missed a compat removal
Removed apps/pages/ (bug 999146)
remove apps/discovery/ (bug 999130)