fix: correct brotli options format (#165)

* fix: correct brotli options format

3d205cd didn't actually fix the default compression issue described in #121 because the zlib format expects quality to be inside [an option called `params`](https://nodejs.org/api/zlib.html#class-brotlioptions)

* tests: update defaults test

* chore: remove trailing whitespace

Author: patrickhulce

__tests__/defaults.js

@@ -8,5 +8,5 @@ test('default brotli param quality should be 4', () => {
   const middleware = createCompressMiddleware()
   assert(Array.isArray(middleware.preferredEncodings))
   assert(middleware.encodingOptions)
-  assert.strictEqual(middleware.encodingOptions.br[zlib.constants.BROTLI_PARAM_QUALITY], 4)
+  assert.strictEqual(middleware.encodingOptions.br.params[zlib.constants.BROTLI_PARAM_QUALITY], 4)
 })

lib/encodings.js

@@ -89,7 +89,9 @@ Encodings.encodingMethodDefaultOptions = {
   gzip: {},
   deflate: {},
   br: {
-    [zlib.constants.BROTLI_PARAM_QUALITY]: 4
+    params: {
+      [zlib.constants.BROTLI_PARAM_QUALITY]: 4
+    }
   }
 }