docker build error

[jmvera255]

@mcilwain
When I build a pepmeld docker image with the current version of requirements.txt I get an error related to Cython, e.g.

#10 130.3     Processing numpy/random/_bounded_integers.pxd.in
#10 130.3     Processing numpy/random/bit_generator.pyx
#10 130.3     Traceback (most recent call last):
#10 130.3       File "/tmp/easy_install-e34r8zg5/numpy-1.20.2/tools/cythonize.py", line 59, in process_pyx
#10 130.3         from Cython.Compiler.Version import version as cython_version
#10 130.3     ModuleNotFoundError: No module named 'Cython'

I was able to successfully build the docker image with the following changes

• add RUN command to Dockerfile to update pip
• remove version numbers from all python packages in requirements.txt except pandas==1.2.2 and biopython==1.78