zhenya mi

#### Additional changes I reformatted code to be below 90 characters line length limit. I also added a test to validate injected event handling in priority event loop. This test...

#### Valgrind output I ran Valgrind with the new test. ```bash $ valgrind ./bin/flb-it-flb_event_loop ... Test test_inject_event_priority_loop... ==2428== Conditional jump or move depends on uninitialised value(s) ==2428== at 0x40B2CF: flb_event_load_bucket_queue_event...

Ready for review. I don't know what to do about the MacOS test failure. I see some build issues are being worked on in other PRs.