Add initial LogfileInput tests, and add configurability to the file reading intervals so
the tests can still run quickly.
Merge pull request #117 from mozilla-services/features/logfile-input-tests

Initial LogfileInput tests
Adjust to fewer log file lines.
Add pipeline_runner.go doc strings.
Doc strings for router.go.
Merge branch 'dev' into features/doc-string-audit

Conflicts:
	pipeline/logfile_input.go