Add env

[josephmancuso]

This PR adds a new env function which helps convert environment types to their respective boolean or int values.

we are currently doing this:

import os
...
DATABASES = {
    'default': {
        'driver': os.environ.get('DB_DRIVER', 'default'),
        'host': os.environ.get('DB_HOST', 'default'),
        'port': os.environ.get('DB_PORT', 'default'),
    }
}

Now we can do this:

from masonite import env
...
DATABASES = {
    'default': {
        'driver': env('DB_DRIVER', 'default'),
        'host': env('DB_HOST', 'default'),
        'port': env('DB_PORT', 'default'),
    }
}

Not only does this shorten things down a bit but it ALSO will type cast as well. So an environment variable of '3306' (string) will actually convert to 3306 (int)

Also an environment variable of 'True' or 'true' will convert to the actual boolean of True

[coveralls]

Coverage increased (+0.03%) to 91.869% when pulling 968851a on add-env into 40715fb on develop.

[josephmancuso]

This actually also solves the problem of 'False' actually being True because it is a string