Initial oss-fuzz integration. (#529)

Signed-off-by: davkor <david@adalogics.com>

fuzz/fuzz_targets/fuzz_hpack.rs

@@ -0,0 +1,6 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data_: &[u8]| {
+    let _decoder_ = h2::fuzz_bridge::fuzz_logic::fuzz_hpack(data_);
+});