TestValidator

[agouin]

Functionality improvements:

• Removes the requirement of an empty home directory to execute config commands. Adds the intended safety of not overwriting the config.yaml without being certain, so the -o/--overwrite flag will be necessary in order to overwrite the existing config when using config init.
• Shows success message now when config.yaml is initialized
• cosigner address $BECH32_BASE_PREFIX command will now additionally show the PubKey and valconspub address, which can be used for gentx and tx staking create-validator

Test improvements:

• Introduces a new struct, TestValidator, to organize test horcrux validators with their signers and sentries, and provide helper methods to simplify test logic.
• Adds TestChainPureHorcrux to test a chain with only horcrux validators
• Uses AutoRemove: false on docker containers so that the testing framework can pull logs from container stdin/stdout and log them out in the case of errors before removing the containers.
• Adds val index to container names

[mark-rushakoff]

Most of this is beyond my expertise in the domain as of yet, but I left a few comments on some basic style points.