Move tox and other configuration files to root folder. Add eachdist to make it
easier to handle operations with different packages.
The eachdist is taken from opentelemetry but slighty modified to avoid ignoring
a given path.
OpenTelemetry doesn't support Python 2.7. Removing it from the tests and removing contrib packages that don't support Python 3. In this change:
- removing pylons contrib
- removing mysqldb contrib
- updating minimum versions of flask (>=1.0), gevent (>=1.1)
Signed-off-by: Alex Boten <aboten@lightstep.com>
