Gets a specific leaf by the leaf Index

`rekor getleaf --index ($index)

Add an update command to fetch and store the latest rootTreeHash/Size.

If we have a previous set of values, we also check the consistency proof between
these two to make sure the tree has not been tampered with.

General clean up

* Remove unsed files (log_server, inclusion (which is now get)

* Add some meaningful text to CLI help

* Make the README more specific to the new role of the CLI (direct
connections to rekor server)

Proof

Switch the get command over to use the server, and refactor a bit.

Hook these up to the server instead of the trillian DB.

Basic CI Setup

Mention refactor

map server not needed

Implements uber/zap logging

Merge pull request #3 from lukehinds/readme-fixes

Add more details to README

Basic inclusion command for GetInclusionProofByHash

Readme amendments

Provide links for related projects

Add more details to README

Remove incorrect aws-sdk dep