text: Title: Runtime error when using python SDK with `alembic==1.4.0`
  Body: ## 🐛 Bug
  
  <!-- A clear and concise description of what the bug is. -->
  [`python -m alembic` doesn't work until version >= 1.5.0](https://github.com/sqlalchemy/alembic/releases/tag/rel_1_5_0), and the code errors out when creating a Run through the python SDK if using 1.4.0.
  
  The error:
  ```
  /opt/miniconda/lib/python3.7/site-packages/aim/sdk/run.py:823: in __init__
  --
    | super().__init__(run_hash, repo=repo, read_only=read_only, experiment=experiment, force_resume=force_resume)
    | /opt/miniconda/lib/python3.7/site-packages/aim/sdk/run.py:275: in __init__
    | super().__init__(run_hash, repo=repo, read_only=read_only, force_resume=force_resume)
    | /opt/miniconda/lib/python3.7/site-packages/aim/sdk/base_run.py:35: in __init__
    | self.repo = get_repo(repo)
    | /opt/miniconda/lib/python3.7/site-packages/aim/sdk/repo_utils.py:23: in get_repo
    | repo = Repo.from_path(repo, init=True)
    | /opt/miniconda/lib/python3.7/site-packages/aim/sdk/repo.py:205: in from_path
    | repo = Repo(path, read_only=read_only, init=init)
    | /opt/miniconda/lib/python3.7/site-packages/aim/sdk/repo.py:148: in __init__
    | self.structured_db.run_upgrades()
    | /opt/miniconda/lib/python3.7/site-packages/aim/storage/structured/db.py:94: in run_upgrades
    | upgrade_database(self.db_url)
    | _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
    |  
    | db_url = 'sqlite:////tmp/tmpmub5nsyq/.aim/run_metadata.sqlite'
    |  
    | def upgrade_database(db_url):
    | migration_env = os.environ.copy()
    | migration_env['AIM_RUN_META_DATA_DB_URL'] = db_url
    |  
    | cmd = create_migration_cmd()
    |  
    | migration_command = subprocess.Popen(cmd, env=migration_env, universal_newlines=True)
    | migration_command.communicate()
    | exit_code = migration_command.wait()
    | if exit_code != 0:
    | >           raise subprocess.SubprocessError(f'Database upgrade failed with exit code {exit_code}')
    | E           subprocess.SubprocessError: Database upgrade failed with exit code 1
  
  ERROR: No module named alembic.__main__; 'alembic' is a package and cannot be directly executed
  ```
  
  ### To reproduce
  
  <!-- Reproduction steps. -->
  1. Install `aim` with `alembic==1.4.0`
  2. Create a `Run` object with the python SDK.
  
  ### Expected behavior
  
  <!-- Fill in expected behavior.  -->
  
  ### Environment
  
  - Aim Version (e.g., 3.0.1)
  - Python version: 3.8
  - pip version
  - OS (e.g., Linux): MacOS, Linux
  - Any other relevant information
  
  ### Additional context
  
  <!-- Add any other context about the problem here. -->
  