Switch our python package management solution to poetry.

Mainly because it has better support for installing the packages from
different python versions.

It also has better dependency resolver than Pipenv. And supports modern
standard for python dependency management. This includes usage of
pyproject.toml for project specific configuration instead of per
tool conf files. See following links for details:
 https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/
 https://www.python.org/dev/peps/pep-0518/

scripts/pysync

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+# This is a helper script for setting up/updating our python environment.
+# It is intended to be a primary endpoint for all the people who want to
+# just setup test environment without going into details of python package management
+
+poetry install --no-root # this installs dev dependencies by default