Fix python dependencies

backend/requirements.txt

@@ -1,18 +1,17 @@
-Pillow>=8.1.1
-einops == 0.3.0
-h5py == 2.8.0
-imageio == 2.9.0
-matplotlib == 3.3.2
-opencv_python
-scikit_image == 0.17.2
-scipy == 1.5.2
-sklearn
-torch == 1.7.0
-torchvision == 0.8.1
-tqdm == 4.51.0
-transformers == 3.5.1
-utils == 1.0.1
-Pygments>=2.7.4
+Pillow
+einops
+h5py
+imageio
+matplotlib
+opencv-python
+scikit-image
+scipy
+scikit-learn
+torch
+torchvision
+tqdm
+transformers
+Pygments
 flask
 flask-cors
 numpy