Update bindgen requirement from 0.55 to 0.56 (#25)

dependabot[bot] · web-flow · commit 5fb507fe6f1e · 2020-12-04T04:35:57.000Z
diff --git a/Cargo.toml b/Cargo.toml
@@ -14,5 +14,5 @@ license = "LGPL-3.0"
 [dependencies]
 
 [build-dependencies]
-bindgen = "0.55"
+bindgen = "0.56"
 cmake = "0.1"
