Use networkx 2.7 and replace deprecated fcn (#189)

Fix #187

Author: rly

requirements/default.txt

@@ -1,6 +1,6 @@
 numpy>=1.11
 scipy>=0.18
-networkx>=1.11
+networkx>=2.7
 numba>=0.29
 pandas>=0.24
 openpyxl>=2.4

setup.cfg

@@ -48,7 +48,7 @@ include_package_data = True
 install_requires =
     imageio>=2.0
     matplotlib>=3.0
-    networkx>=2.0
+    networkx>=2.7
     numba>=0.50
     numpy>=1.16.5
     pandas>=1.0

src/skan/draw.py

@@ -399,7 +399,7 @@ def overlay_skeleton_networkx(
     if image is not None:
         cmap = cmap or 'gray'
         axis.imshow(image, cmap=cmap)
-    gnx = nx.from_scipy_sparse_matrix(csr_graph)
+    gnx = nx.from_scipy_sparse_array(csr_graph)
     # Note: we invert the positions because Matplotlib uses x/y for
     # scatterplot, but the coordinates are row/column NumPy indexing
     positions = dict(zip(range(coordinates.shape[0]), coordinates[:, ::-1]))