enable slack-api with testsuite expected to fail (#5345)
enable slack-api with testsuite expected to fail (#5345)

This reverts commit 872d1086c2b3f4fa753c4bd2c524a4982ec060c7.

massysett/stackage,clinty/stackage,michalkonecny/stackage,asr/stackage,iand675/stackage,fpco/stackage,soenkehahn/stackage,mrkkrp/stackage,Daniel-Diaz/stackage,simonmichael/stackage,jonschoning/stackage