[Bug] Unabel to pip install keplergl

**Describe the bug**
Failed to install keplergl.

**To Reproduce**
Steps to reproduce the behavior:
1. Start Anaconda Prompt
2. Activate virtual env
3. pip install keplergl
4. See error

```
Collecting keplergl
Using cached https://files.pythonhosted.org/packages/2f/a0/ea13a2cc4071fddc91a6ea530d0349e4b943a4a8839209a7facecee37db3/keplergl-0.2.1.tar.gz
Requirement already satisfied: ipywidgets<8,>=7.0.0 in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from keplergl) (7.5.1)
Collecting traittypes>=0.2.1 (from keplergl)
Using cached https://files.pythonhosted.org/packages/9c/d1/8d5bd662703cc1764d986f6908a608777305946fa634d34c470cd4a1e729/traittypes-0.2.1-py2.py3-none-any.whl
Collecting geopandas>=0.5.0 (from keplergl)
Using cached https://files.pythonhosted.org/packages/f7/a4/e66aafbefcbb717813bf3a355c8c4fc3ed04ea1dd7feb2920f2f4f868921/geopandas-0.8.1-py2.py3-none-any.whl
Requirement already satisfied: pandas>=0.23.0 in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from keplergl) (1.0.1)
Collecting Shapely>=1.6.4.post2 (from keplergl)
Using cached https://files.pythonhosted.org/packages/0a/e2/1b7aba5ce9804998581efeab455d8a1a902f992f20d2e15dd4ab0a7db4db/Shapely-1.7.1-cp36-cp36m-win_amd64.whl
Requirement already satisfied: ipykernel>=4.5.1 in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from ipywidgets<8,>=7.0.0->keplergl) (5.3.4)
Requirement already satisfied: nbformat>=4.2.0 in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from ipywidgets<8,>=7.0.0->keplergl) (4.4.0)
Requirement already satisfied: widgetsnbextension~=3.5.0 in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from ipywidgets<8,>=7.0.0->keplergl) (3.5.1)
Requirement already satisfied: ipython>=4.0.0; python_version >= "3.3" in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from ipywidgets<8,>=7.0.0->keplergl) (7.16.1)
Requirement already satisfied: traitlets>=4.3.1 in c:\users\curtis\appdata\local\continuum\anaconda3\envs\tf2a\lib\site-packages (from ipywidgets<8,>=7.0.0->keplergl) (4.3.2)
Collecting fiona (from geopandas>=0.5.0->keplergl)
Using cached https://files.pythonhosted.org/packages/88/62/69347ba2c41b526e1953c4cb66d51170b2869808863c03af202ba0121670/Fiona-1.8.17.tar.gz
ERROR: Complete output from command python setup.py egg_info:
ERROR: A GDAL API version must be specified. Provide a path to gdal-config using a GDAL_CONFIG environment variable or use a GDAL_VERSION environment variable.
----------------------------------------
ERROR: Command "python setup.py egg_info" failed with error code 1 in C:\Users\Curtis\AppData\Local\Temp\pip-install-qwrvdd7o\fiona\
```

**Desktop (please complete the following information):**
- OS: Windows 10

Reproduce the reported `pip install keplergl` failure in an Anaconda environment on Windows 10, focusing on the Fiona dependency and its “A GDAL API version must be specified” error. Check the package installation metadata and dependency setup; done means the package installs successfully without this error.

Written by the indexing model from the issue text.