not using Prometheus naming conventions

[askmike]

Great project! In the hope that this is still maintained: the metrics exposed are not using prometheus naming conventions:

A counter MUST have the following methods:

• inc(): Increment the counter by 1
• inc(double v): Increment the counter by the given amount. MUST check that v >= 0.

While this lib exposes increment. Also the decrease does not obey the convention:

It MUST NOT allow the value to decrease