Fix README link to drone.io status

Closes #24
Fixes for bunchmark_runner

trailing whitespace
generate a list from the filter args
use contains instead of indexOf
print an error if no benchmarks are run because of filter - and set an error exit code of 1
remove seemingly unused annotation
locking down a few things in the runner
Merge pull request #26 from kevmoo/README_tweak

Fix README link to drone.io status
Merge pull request #27 from kevmoo/benchrunner_fixes

Benchrunner fixes