Update wavesurfer.minimap.js (#955)

* Update wavesurfer.minimap.js

renders the minimap without the need to resize the window.
Changed 

        this.wavesurfer.on('ready', this.render.bind(this));

to 

        this.wavesurfer.on('ready', my.render.bind(this));

* Update wavesurfer.minimap.js

added the fixes for the drawPeaks()

* update my.render to this.render

* add parameter check renderOnLoad

check to see if a parameter called "miniRenderOnLoad" is set to true, if it is render the minimap on load.

* Update wavesurfer.minimap.js

* add space after else

* render minimap on load

will update docs and create example for minimap plugin
- minimap should be initialized within the main wavesurfer ready event.

plugin/wavesurfer.minimap.js

@@ -94,7 +94,8 @@ WaveSurfer.Minimap = WaveSurfer.util.extend({}, WaveSurfer.Drawer, WaveSurfer.Dr
 
     bindWaveSurferEvents: function () {
         var my = this;
-        this.wavesurfer.on('ready', this.render.bind(this));
+        // render on load
+        this.render();
         this.wavesurfer.on('audioprocess', function (currentTime) {
             my.progress(my.wavesurfer.backend.getPlayedPercents());
         });