Create caliper microbenchmarks
Count numeric characters before processing formattedMessage

This is to optimize for the case where there aren't enough digits in
the string to form a credit card number. This avoids the cost of regular
expression matching.

We assume that the shortest possible credit card number has 13 digits.
Increase microbenchmark warm up time to 20 seconds

This is to avoid Hotspot compilation during timing which was
consistently happening when using the default 10 second warm up.