updated README with information for python3 version

README.txt

@@ -7,7 +7,7 @@ PhageTerm.py - run as command line in a shell
 VERSION
 =======
 
-Version 3.1.0
+Version 4.0.0
 
 
 INTRODUCTION
@@ -35,11 +35,18 @@ Since version 3.0.0, PhageTerm can work in 2 modes:
 - mono machine mode (parallelization on several cores on tne same machine).
 - multi machine mode (parallelization on several machines, using intermediate files for data exchange).
 The default mode is mono machine.
+Version 3.0.0 up to version 4.0 work with python 2.7
+
+Since version 4.0, PhageTerm works with python 3.7
+
+
 
 
 PREREQUISITES
 =============
 
+For version 3.0 up to version 4.0 (not included)
+
 Unix/Linux
 
 - Python      2.7.X
@@ -52,12 +59,30 @@ Unix/Linux
 - reportlab   3.3.0
 
 A conda virtualenv containing python2.7 and all dependencies is provided for convenience so that users
-don't need to install anything else than miniconda.
+don't need to install anything else than miniconda or conda.
+
+
+For version 4.0
+
+Unix/Linux
+
+- Python	3.7
+- matplotlib  
+- numpy       
+- pandas      
+- sklearn     
+- scipy       
+- statsmodels 
+- reportlab   
+
+A conda virtualenv containing python3.7 and all dependencies is provided for convenience so that users
+don't need to install anything else than miniconda or conda.
+
 
 USING THE CONDA VIRTUALENV
 ==========================
 
-First install miniconda (you don't even need to have python 2.7 installed on your machine for that;
+First install miniconda (you don't even need to have python 2.7 or python 3.7 installed on your machine for that;
 miniconda contains it): https://docs.conda.io/en/latest/miniconda.html
 
 Then, create the miniconda environment from the PhageTerm_env.yml file: