adding ability to define the inital status of consul checks

[asgolding]

Would like to add the ability to define the inital check status as described in https://www.consul.io/docs/agent/checks.html under the heading "Initial Health Check Status".

I've tested this change and it works.

[asgolding]

I've had a look at the test errors and they don't appear to be related to my change.

[solarkennedy]

Can you add docstring?

[solarkennedy]

ty