This moves the whole checks if everything is running into its own class
and is no longer inside the different functions.
Makes the functions smaller and the healthcheck can be used from the
client only if wanted/needed.
This moves the Kredits initialization to the instance which allows us to
be more flexible with handling contract addresses.
Example:
var k = new Kredits(provider, signer, {Registry: '0xabc'});
k.init().then((kredits) { ...});
var k = new Kredits(provider, signer, {Contributors: '0xabc'})
k.Contributor.add(...);
