The package (actually called pystrain) has been sucesefuly installed under
both python2.7 and python3.6.
Apart from a/the python interpreter, the package will need Numpy and Scipy.
The main program tha computes the strain tensors is located at StrainTool/bin,
named StrainTensor.py. Before you go ahead and use it though, you need to
install the pystrain package.
Go to the StrainTool/pystrain directory and run the command
python setup.py install. You will probably need to do this with root
privileges.
This is the program that actualy does the computations, found under StrainTool/bin.
It may be needed to make it executable before you run it (in a UNIX-like OS,
the following should do chmod +x StrainTensor.py).