Improve tests Telegraf client Timer command of accepting callables
Improve tests Telegraf client Timer command of accepting callables

By using RegExp asserts instead of exact equality assertions for the
metrics, because sometimes the amount of time passed during execution of
the callabes is different than the expectaion, asserting by exact
equality makes the test unstable, failing on some environments,
         sometimes and passing some other times.

sam-media/php-statsd-client,farzadghanei/php-statsd-client