update requirements

requirements.txt

@@ -1,23 +1,24 @@
-matplotlib~=3.1
-numpy~=1.16
-networkx~=2.4
-pandas~=1.0
-pint~=0.10
-plotly~=4.9
-pynrrd~=0.4.2
-pypng~=0.0.18
-PyQt5~=5.15
-requests~=2.20
-Shapely~=1.6.0
-seaborn~=0.10
-setuptools~=49.6
-scipy~=1.5
-six~=1.11
-tqdm~=4.45
-vispy~=0.6.4
-typing-extensions~=3.7.4
-trimesh~=3.8
-ncollpyde~=0.11
+matplotlib>=3.2
+morphops>=0.1.11
+numpy>=1.16
+networkx>=2.4
+pandas>=1.0
+pint>=0.10
+plotly>=4.9
+pynrrd>=0.4.2
+pypng>=0.0.18
+PyQt5>=5.15
+requests>=2.20
+Shapely>=1.6.0
+seaborn>=0.10
+setuptools>=50.6
+scipy>=1.5
+six>=1.11
+tqdm>=4.45
+vispy>=0.6.4
+typing-extensions>=3.7.4
+trimesh>=3.8
+ncollpyde>=0.11
 # Below are optional dependencies
 # py2cytoscape~=0.7.0
 # pyoctree~=0.2.10