[Integrated] RFR: merge-bot: specs can have prerequisites

[Erik Helin]

Changeset: 0c2920e3
Author:    Erik Helin <ehelin at openjdk.org>
Date:      2020-04-27 11:57:43 +0000
URL:       https://git.openjdk.java.net/skara/commit/0c2920e3

merge-bot: specs can have prerequisites

Reviewed-by: rwestberg

! bots/merge/src/main/java/org/openjdk/skara/bots/merge/MergeBot.java
! bots/merge/src/main/java/org/openjdk/skara/bots/merge/MergeBotFactory.java
! bots/merge/src/test/java/org/openjdk/skara/bots/merge/MergeBotTests.java