Adding mysql database healthcheck.

I would like to contribute and add a request tracing - https://opentracing.io/

I suggest putting the example and checks in other repositories, since go.mongodb.org/mongo-driver looks like a very unnecessary dependency for many projects.

It doesn't look like there's a way to set the top-level pass/fail/warn status at the minute as it's forced to Pass in the HTTP handler:

For my use-case it'd be ideal if that was generated automatically from the statuses of the component checks (i.e., Fail if any checks fail, else Warn if any checks warn, else Pass).

Hi! I came across an error due to updating the path of the dependent library.

go: my_package imports
        github.com/nelkinda/health-go tested by
        github.com/nelkinda/health-go.test imports
        github.com/christianhujer/assert tested by
        github.com/christianhujer/assert.test imports
        github.com/DATA-DOG/godog: github.com/DATA-DOG/[email protected]: parsing go.mod:
        module declares its path as: github.com/cucumber/godog
                but was required as: github.com/DATA-DOG/godog

I recommend changing
from: github.com/christianhujer/assert
to: github.com/stretchr/testify/assert
Thanks!