Also add basic skeleton implementation for the gitflow-feature and gitflow-release subcommands.
diff --git a/gitflow-hotfix b/gitflow-hotfix
index aa38ab6..aae2546 100755
--- a/gitflow-hotfix
+++ b/gitflow-hotfix
@@ -5,8 +5,18 @@
 	echo "       gitflow finish hotfix <release>"
 }
 
+parse_args() {
+	RELEASE="$1"
+	if [ "$RELEASE" = "" ]; then
+		echo "Missing argument <release>."
+		usage
+		exit 1
+	fi
+}
+
 start() {
 	# TODO
+	parse_args "$@"
 	gitflow_check_clean_working_tree
 	echo "git checkout -b hotfix-$RELEASE master"
 	echo "Bump version number"
@@ -15,6 +25,7 @@
 
 finish() {
 	# TODO
+	parse_args "$@"
 	gitflow_check_clean_working_tree
 	echo "git checkout master"
 	echo "git merge --no-ff hotfix-$RELEASE"