Improve Bugzilla attachment setup
Improve Bugzilla attachment setup

1) Prepare to attach tests both as bytes and string format
2) Add the necessary content type setting

renatahodovan/fuzzinator,akosthekiss/fuzzinator,akosthekiss/fuzzinator,renatahodovan/fuzzinator,renatahodovan/fuzzinator,akosthekiss/fuzzinator,akosthekiss/fuzzinator,renatahodovan/fuzzinator