89ce16b removed a few package installations from the dockerfiles for
building python artifacts. Revert them.
Revert certain package install removal from python artifact dockerfiles
Due to a recent change (Feb 2018) in Github's policy to discontinue
support for weak cryptographic standards, older git versions stopped
working with Github repositories. The Dockerfiles for building python
artifacts currently uses git 2.0.5, that fails with an error `tlsv1
alert protocol version`.
The CentOS image by the latest source Dockerfile, `manylinux` comes
with the latest version of git as well, removing the need to manually
build git from source.
Before, namespace packages would break in auditwheel due to a
superfluous check (fixed in the commit referenced in the Dockerfiles).
Now, the auditwheel used in the manylinux1-support Docker images can
handle namespace packages, and we may thus use them. This should
alleviate future user pain w.r.t. installation of grpcio-tools causing
loss of grpcio files and vice versa (e.g. requiring a reinstall of
grpcio following installation of grpcio-tools).
The source code is moved from src/python to
src/python/src. A setup.py is added at
src/python. The build_python.sh and
run_python.sh scripts are updated to build
and run the Python tests by building a
package and installing it in the developer's
Python 2.7 virtual environment.