Allow URLs to be customized

[OdinsPlasmaRifle]

Allow a HEALTHCHECK configuration object to be defined that allows custom URLs to be defined for "liveness" (healthz) and "readiness".

HEALTHCHECK = {
    "LIVENESS_PATH": "/livenessz/",
    "READINESS_PATH": "/readinessz/",
}

Default to /livenessz/ and /readinessz/.

[OdinsPlasmaRifle]

Would it be possible to have the path to accept regex (to allow closed AND open slashes at the same time)

[nanderv]

Also, please make the default healthz, readyz, livez, as these are a standard.