title: Requested MovieWriter (ffmpeg) not available even when I installed it
body: <p>I am running this command.</p>
  <pre><code>import bar_chart_race as bcr
  bcr.bar_chart_race(df=covid_df,filename=None,figsize=(3.5,3),title='Covid-19 Cases by State',n_bars=10)
  </code></pre>
  <p>Getting the below error</p>
  <pre><code>Exception: You do not have ffmpeg installed on your machine. Download
                              ffmpeg from here: https://www.ffmpeg.org/download.html.
                              
                              Matplotlib's original error message below:
  
                              Requested MovieWriter (ffmpeg) not available
  
  </code></pre>
  <p>Have already installed the module</p>
  <pre><code>D:\py\Scripts&gt;pip install ffmpeg-python
  Requirement already satisfied: ffmpeg-python in d:\py\lib\site-packages (0.1)
  
  D:\py\Scripts&gt;
  </code></pre>