text: Title: Clustergram row labels change heatmap values/colors
  Body: Passing a list of labels to `row_labels` seem to change the values that are plotted in the heatmap rather than just adding a textual label on the side.
  
  ```python
  import dash_bio as db
  import plotly.express as px
  
  iris = px.data.iris()
  db.Clustergram(iris.select_dtypes('number').to_numpy())
  ```
  
  ![image](https://user-images.githubusercontent.com/4560057/69491183-cd8f7880-0e91-11ea-8166-d4c782d796ad.png)
  
  In the plot above there it one value per row in each color. Below, rows are grouped together so that there are are only three values/colors per column.
  
  ```python
  db.Clustergram(iris.select_dtypes('number').to_numpy(), row_labels=iris['species'].to_list())
  ```
  
  ![image](https://user-images.githubusercontent.com/4560057/69491175-aafd5f80-0e91-11ea-87c1-d6e59872286a.png)
  
  The font size of the labels also don't adjust to the size of the plot. I have to change the height to 2000 before I can read what they say:
  
  ![image](https://user-images.githubusercontent.com/4560057/69491228-79d15f00-0e92-11ea-9b93-d9f02236adde.png)
  
  ```
  -----
  dash      	1.6.1
  dash_bio  	0.4.4
  dash_core_components	1.5.1
  dash_html_components	1.0.2
  numpy     	1.17.3
  pandas    	0.25.3
  plotly    	4.3.0
  -----
  IPython   	7.9.0
  jupyter_client	5.3.3
  jupyter_core	4.6.1
  notebook  	6.0.1
  -----
  Python 3.8.0 | packaged by conda-forge | (default, Nov 22 2019, 19:11:38) [GCC 7.3.0]
  ```