Latest swagger command from upstream.

Author: jqr

script/swagger

@@ -14,6 +14,10 @@ fi
 
 (
   cd swagger-codegen
+  if [[ "${#SWAGGER_CODGEN_REVISION}" -lt 40 ]]; then
+    # resolve git tags / branch names
+    SWAGGER_CODGEN_REVISION=$(git show "$SWAGGER_CODGEN_REVISION" --format="%H")
+  fi
   if [[ $(cat .git/HEAD) != "$SWAGGER_CODGEN_REVISION" ]]; then
     git fetch
     git checkout "$SWAGGER_CODGEN_REVISION"