This changeset breaks the API of Attack in order to decouple Reporters
and the Attack function. Attack now returns a slice with
non-deterministic order of Results which one can use on the calling code
with or without Reporters, hence making it much more useful on a library
usage setting.
These developments could be of interest to issue #11 which was closed in
the past.
Skips lines that start with `//`, to allow commments in `targets.txt`. This is
handy when you want to attach a comment on why a specific endpoint is tested, in
a `targets.txt` used as part of a benchmark suite.
