add percentile check
allow for nulls in average check with -n setting
replace map with each as per @nstielau review comment
allow each check to be ether a less than or greater than check using -g flag
fix typo in default value for percentile check
add percent above average check
fix CI issues
add ability to use mean of the last N datapoints as the last value for average and percentile checks
fix bug when returning multiple last values
Merge pull request #259 from janstenpickle/master

New features for graphite check