P8 support

[td202]

Purpose

Closes #72

Support protocol version 8.

Changes

• The configure_baker operation can have metadata with the suspended boolean, indicating when a validator is manually suspended or resumed.
• New validator_primed_for_suspension and validator_suspended operation types indicate when a validator is primed for suspension or suspended automatically as part of the tokenomics transaction.
• Update dependencies
• Change /node/options to report the node and middleware versions accurately. (i.e. query the node for the node version, and use the Cargo.toml version for the middleware version.)
• Bump the version number.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.

[drsk0]

Looks good!