Merge remote-tracking branch 'upstream/master' into commit_boost_gen_…

…proxy

# Conflicts:
#	commandline/src/main/java/tech/pegasys/web3signer/commandline/subcommands/Eth2SubCommand.java
#	core/src/main/java/tech/pegasys/web3signer/core/Eth2Runner.java
#	signing/src/main/java/tech/pegasys/web3signer/signing/ArtifactSignerProvider.java
#	signing/src/main/java/tech/pegasys/web3signer/signing/config/DefaultArtifactSignerProvider.java
#	signing/src/test/java/tech/pegasys/web3signer/signing/config/DefaultArtifactSignerProviderTest.java