Assign RUSTSEC-2018-0004 to claxon

Original PR:

#54

Author: tony-iqlusion

crates/claxon/RUSTSEC-0000-0000.toml renamed to crates/claxon/RUSTSEC-2018-0004.toml

@@ -1,5 +1,5 @@
 [advisory]
-id = "RUSTSEC-0000-0000"
+id = "RUSTSEC-2018-0004"
 package = "claxon"
 date = "2018-08-25"
 title = "Malicious input could cause uninitialized memory to be exposed"