title: collection.Mutablemapping Error in pyrebase Import
body: <p>I have installed pyrebase library and tried importing it Like</p>
  <pre><code>import pyrebase
  </code></pre>
  <p>It gives following Error and i dont know how to fix it!</p>
  <pre><code>Traceback (most recent call last):
    File &quot;fire.py&quot;, line 1, in &lt;module&gt;
      import pyrebase
    File &quot;env\lib\site-packages\pyrebase\__init__.py&quot;, line 1, in &lt;module&gt;
      from .pyrebase import initialize_app
    File &quot;env\lib\site-packages\pyrebase\pyrebase.py&quot;, line 1, in &lt;module&gt;
      import requests
    File &quot;env\lib\site-packages\requests\__init__.py&quot;, line 63, in &lt;module&gt;
      from . import utils
    File &quot;env\lib\site-packages\requests\utils.py&quot;, line 27, in &lt;module&gt;
      from .cookies import RequestsCookieJar, cookiejar_from_dict
    File &quot;env\lib\site-packages\requests\cookies.py&quot;, line 172, in &lt;module&gt;
      class RequestsCookieJar(cookielib.CookieJar, collections.MutableMapping):
  
  AttributeError: module 'collections' has no attribute 'MutableMapping'
  </code></pre>
  <p>Tried following some stack overflow advice but those wewe not specific.</p>