Add missing feature

Signed-off-by: Joe Grund <[email protected]>

Author: Joe Grund

commandeer-macros/Cargo.toml

@@ -15,4 +15,4 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "2.0", features = ["extra-traits"] }
+syn = { version = "2.0", features = ["extra-traits", "full"] }