Drop a-iterable and call-thru dependencies

Author: surol

package.json

@@ -50,8 +50,6 @@
   },
   "dependencies": {
     "@hatsy/http-header-value": "^3.4.0",
-    "@proc7ts/a-iterable": "^2.8.0",
-    "@proc7ts/call-thru": "^4.1.0",
     "@proc7ts/primitives": "^1.2.0"
   },
   "engines": {

src/http/util/add-response-header.ts

@@ -2,7 +2,6 @@
  * @packageDocumentation
  * @module @hatsy/hatsy
  */
-import { mapIt } from '@proc7ts/a-iterable';
 import { arrayOfElements, elementOrArray } from '@proc7ts/primitives';
 import { ServerResponse } from 'http';
 
@@ -17,7 +16,7 @@ import { ServerResponse } from 'http';
  */
 export function addResponseHeader(response: ServerResponse, name: string, value: string): void {
 
-  const oldValues = mapIt(arrayOfElements(response.getHeader(name)), String);
+  const oldValues = arrayOfElements(response.getHeader(name)).map(String);
   const newValues = elementOrArray(new Set<string>(oldValues).add(value))!;
 
   response.setHeader(name, newValues);