Refactor report

Feeling things out for now. @eric, do you have any thoughts on adding `#report` to meters? It's spiked on `Counter` and `Meter` so far.
While we're doing major refactoring here and `metriks` is still `0.9.x` which according to semver means  that `Anything may change at any time.`, how about unifying all reporter's constructors and accepting only one, options hash, argument?