Update requirements.txt

docs/requirements.txt

@@ -1,37 +1,4 @@
 ipykernel
 nbsphinx
 
-astropy
-bandit
-black
-black[jupyter]
-bs4
-cartopy
-coverage
-coveralls
-flake8
-flask
-folium
-forex_python
-geojsoncontour
-geonetworkx
-geopandas
-gtfs_kit
-haversine
-isort
-ipfn
-ipywidgets
-matplotlib
-mesa
-movingpandas
-networkx
-numpy
-pandas
-pyproj
-pyrosm
-pytest
-pytest-cov
-requests
-shapely
-us
-werkzeug
+git+https://github.com/davidbailey/dpd.git