trying fixing numpy version

container/singularity/cc_py37.def

@@ -62,6 +62,7 @@ From: centos:8
     source activate py37
 
     # conda-specific packages (~1 min)
+    conda install numpy==1.19.2                      # we fix numpy version because of TF
     conda install -y -c conda-forge rdkit            # Open-Source Cheminformatics Software
     conda install -y -c openbabel openbabel          # chemical toolbox
     conda install -y mkl-service                     # change the number of CPU’s MKL is using
@@ -107,7 +108,7 @@ faiss.Kmeans(10, 20).train(numpy.random.rand(1000, 10).astype(numpy.float32))"'
     pip install scikit-learn                      # entry level ML in python
     pip install gensim                            # topic modelling word2vec
     if ! test_faiss; then printf -- "\033[31m ERROR: faiss is failing! \033[0m\n"; else printf -- '\033[32m SUCCESS: faiss is working correctly. \033[0m\n'; fi
-    pip install tensorflow==2.4.2                 # neural network library
+    pip install tensorflow                        # neural network library
     if ! test_faiss; then printf -- "\033[31m ERROR: faiss is failing! \033[0m\n"; else printf -- '\033[32m SUCCESS: faiss is working correctly. \033[0m\n'; fi
     pip install adanet                            # automl for NN
     pip install keras                             # NN API