Update requirements.txt

Author: LiamConnors

doc/requirements.txt

@@ -4,7 +4,7 @@ ipywidgets==7.7.2
 jupyter-client<7
 jupyter
 notebook
-pandas==1.1.3
+pandas==1.1.5
 statsmodels==0.12.1
 scipy==1.5.4
 patsy==0.5.1
@@ -16,7 +16,7 @@ pyshp==2.1.2
 shapely==1.7.1
 psutil
 requests
-networkx
+networkx==2.6.3
 squarify
 scikit-image==0.18.1
 scikit-learn