Update processer word spelling

[koola]

Fixed spelling mistake:

Prosesser => Processor

[koola]

Assuming this is a spelling mistake, as per Effective Go:

Interface names¶ By convention, one-method interfaces are named by the method name plus an -er suffix or similar modification to construct an agent noun: Reader, Writer, Formatter, CloseNotifier etc.

[anthdm]

Ok makes sense, will merge this soon.