fix: solve compatibility issues with older browser versions

- Firefox 52 does not support the OfflineAudioContext constructor
- versions before Chrome 62, Firefox 57, and Opera 42 do not support
passing OfflineAudioContext parameters as a single object

Closes #3.

package.json

@@ -31,7 +31,7 @@
   },
   "browserslist": [
     "Chrome >= 55",
-    "Firefox >= 52",
+    "Firefox >= 53",
     "FirefoxAndroid >= 57",
     "Opera >= 42"
   ],

src/solve/main.js

@@ -49,12 +49,12 @@ async function prepareAudio(audio) {
   const data = await ctx.decodeAudioData(audio);
   await ctx.close();
 
-  const offlineCtx = new OfflineAudioContext({
+  const offlineCtx = new OfflineAudioContext(
     // force mono output
-    numberOfChannels: 1,
-    length: 16000 * data.duration,
-    sampleRate: 16000
-  });
+    1,
+    16000 * data.duration,
+    16000
+  );
   const source = offlineCtx.createBufferSource();
   source.buffer = data;
   source.connect(offlineCtx.destination);