include node_modules so release .zip is deployable

node_modules/@smithy/signature-v4/dist-es/headerUtil.js

@@ -0,0 +1,26 @@
+export const hasHeader = (soughtHeader, headers) => {
+    soughtHeader = soughtHeader.toLowerCase();
+    for (const headerName of Object.keys(headers)) {
+        if (soughtHeader === headerName.toLowerCase()) {
+            return true;
+        }
+    }
+    return false;
+};
+export const getHeaderValue = (soughtHeader, headers) => {
+    soughtHeader = soughtHeader.toLowerCase();
+    for (const headerName of Object.keys(headers)) {
+        if (soughtHeader === headerName.toLowerCase()) {
+            return headers[headerName];
+        }
+    }
+    return undefined;
+};
+export const deleteHeader = (soughtHeader, headers) => {
+    soughtHeader = soughtHeader.toLowerCase();
+    for (const headerName of Object.keys(headers)) {
+        if (soughtHeader === headerName.toLowerCase()) {
+            delete headers[headerName];
+        }
+    }
+};