Prompt CLI updates

[aaronjudd]

On start of CLI we should check for updates, rather than the prompt that appears after the command has ran and started reaction. This would help with common version related errors to be reported less often -> it's very common for the update message to be ignored (gasp).

One approach:

If there is an update, block the remaining process with prompt:

Update to CLI required, exit now and update? Y/n".

where Yes is the default.