missing pymysql and SQLAlchemy in requirements.txt

[Radoslaw Smigielski]

When you try install osprofiler in isolated virtual env or separate container, the installation will complete but first time you run osprofiler you will end up with below error:

$ osprofiler trace show --connection-string mysql+pymysql://profiler:password@[fd00:f00c::c0a8:e06]/profiler --html e76f4cfe-75e5-4a9a-af20-bbe1edd7c164
To use this command, install 'SQLAlchemy'
Traceback (most recent call last):
  File "/home/radek/tmp/venv3-osprofiler2/lib64/python3.6/site-packages/osprofiler/drivers/sqlalchemy_driver.py", line 33, in __init__
    from sqlalchemy import create_engine
ModuleNotFoundError: No module named 'sqlalchemy'
Failed to create engine/connection and setup intial database tables
Traceback (most recent call last):
  File "/home/radek/tmp/venv3-osprofiler2/lib64/python3.6/site-packages/osprofiler/drivers/sqlalchemy_driver.py", line 62, in __init__
    self._engine = create_engine(connection_str)
UnboundLocalError: local variable 'create_engine' referenced before assignment
To use this command, you should install 'SQLAlchemy'

The problem is missing:
  +pymysql
  +SQLAlchemy
in requirements.txt file.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/656056

[OpenStack Infra (hudson-openstack)]

Change abandoned by Stephen Finucane (<email address hidden>) on branch: master
Review: https://review.opendev.org/656056
Reason: -W for quite some time. I'm going to abandon to keep our review queue sane