title: Pandas IntervalIndex get_loc throws KeyError when label equals bound of interval
body: <p>I have the following IntervalIndex for a df called <code>rates_info</code>:</p>
  <pre><code>rates_info.index
  Out[173]: 
  IntervalIndex([(13.0, 15.0), (15.0, 19.0), (19.0, 24.0)],
                closed='neither',
                dtype='interval[float64]')
  </code></pre>
  <p>The <code>rates_info</code> df looks like this:</p>
  <pre><code>sea_tou       summer_start  summer_end      desc   summer   tou   winter  tou_2
  (13.0, 15.0)           6.0         9.0  shoulder  0.11816  13.0  0.08623   15.0
  (15.0, 19.0)           6.0         9.0    onpeak  0.17246  15.0  0.10858   19.0
  (19.0, 24.0)           6.0         9.0   offpeak  0.06387  19.0  0.06387   24.0
  </code></pre>
  <p>When I try to extract either the <code>summer</code> or <code>winter</code> value for an interval that <em>equals</em> either of the bounds, I am getting a <code>KeyError</code>:</p>
  <pre><code>rates_info.iloc[rates_info.index.get_loc(19)]['winter']
  Traceback (most recent call last):
  
    File &quot;&lt;ipython-input-169-cb4c278084f1&gt;&quot;, line 1, in &lt;module&gt;
      rates_info.iloc[rates_info.index.get_loc(19)]['winter']
  
    File &quot;C:\ProgramData\Anaconda3\lib\site-packages\pandas\core\indexes\interval.py&quot;, line 730, in get_loc
      raise KeyError(key)
  
  KeyError: 19
  </code></pre>
  <p>or</p>
  <pre><code>rates_info.iloc[rates_info.index.get_loc(13)]['winter']
  Traceback (most recent call last):
  
    File &quot;&lt;ipython-input-184-5bafb5e11739&gt;&quot;, line 1, in &lt;module&gt;
      rates_info.iloc[rates_info.index.get_loc(13)]['winter']
  
    File &quot;C:\ProgramData\Anaconda3\lib\site-packages\pandas\core\indexes\interval.py&quot;, line 730, in get_loc
      raise KeyError(key)
  
  KeyError: 13
  </code></pre>
  <p>When I use a value that is <em>between</em> the intervals, it works fine:</p>
  <pre><code>rates_info.iloc[rates_info.index.get_loc(20)]['winter']
  Out[185]: 0.06387
  </code></pre>
  <p>or</p>
  <pre><code>rates_info.iloc[rates_info.index.get_loc(16)]['winter']
  Out[186]: 0.10858
  </code></pre>
  <p>Any idea what might be happening here?</p>