Merge branch 'master' into next
* master:
RevWalk: stop mixing lines of history in topo sort
Upgrade plexus-compiler-{eclipse|javac|javac-errorprone} to 2.8.6
Upgrade maven-shade-plugin to 3.2.2
Removed unused imports
Update API problem filter
Prepare 5.6.2-SNAPSHOT builds
JGit v5.6.1.202002131546-r
Simplify ReftableCompactor
Bump required Bazel version to 2.1.0
Upgrade bazlets to the latest master revision
Change the wildcard import to explicit ones.
Documentation/technical/reftable: improve repo layout
Change-Id: I01e351843ec1edb599c10029249fd90c9960b240
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>