Updated readme to include example usage of crud_table.py

    db.query('SELECT NOW()')

```

### Creating a CRUD table with crud_table.py

```

from common.mixins.postgres import PostgresMixin

from common.database import Database

from common.crud_table import CRUDTable

class users(CRUDTable):

    """Provides CRUD access to the users table"""

    def __init__(self, db):

    """__init__:

    :param db: the database that contains the 'users' table.

    """

    # be sure to define the columns as they appear in the database.

    # in this example, the users table has 6 columns.

    columns = {

        'id': int,

        'email': str,

        'password': str,

        'roles': str,

        'token': str,

        'is_active': bool

    }

    # initialize the super class with the column definition, the schema that

    # the table is in, and the database object.

    super().__init__(columns, schema='public', db)

    # TODO add additional functions for your class here, specific to your needs

class PostgresDatabase(Database, PostgresMixin):

    """The class that allows Database to interact with psycopg2."""

    def __init__(self):

        super().__init__()

        # here we are assigning the CRUD table to the database's 'users'

        # variable and passing the database object to the constructor

        self.users = users(self)

    # TODO add additional functions for your class here, specific to your needs

with PostgresDatabase() as db:

    db.query('SELECT NOW()')

    # this will create a user in the database, with the specified fields and

    # null for the columns not specified

    db.users.create(id=1337, email='admin@test.com', password='*****',

                    is_active=True)

    # this will read the entire user's table 'SELECT * FROM public.users;'

    users_table = db.users.read()

    # this will read only id, and email columns from the users table

    # 'SELECT id, email FROM public.users;'

    columns_users_table = db.users.read(columns=['id', 'email'])

    # data can be read from the database in 'json' format by specifying

    # json=True in your call. The 'json' format returned is a python dictionary

    # that is json serializable

    json_data = db.users.read(json=True)

    # where clauses can be passed as keyword arguments to the call

    # 'SELECT * FROM public.users WHERE id = 1337;

    filtered_users_table = db.users.read(id=1337)

    # to update entries, a where clause must be passed as follows

    # 'UPDATE public.users SET email='update@test.com' WHERE id=1337;'

    db.users.update(where={'id': 1337}, email='update@test.com')

    # to delete entries, a where clause must also be passed. The were clause

    # for a deletion should come in the form of keyword arguments

    # 'DELETE FROM public.users WHERE id=1337;'

    db.users.delete(id=1337)

```

## Testing

Testing for the `common_package` is contained within `/common_package/test/test.py`. This can be accessed by building the test docker compose file with: