Loads .env file into sys.environ.

def load_dot_env():
    """Loads .env file into sys.environ."""
    if not environments.PIPENV_DONT_LOAD_ENV:
        # If the project doesn't exist yet, check current directory for a .env file
        project_directory = project.project_directory or "."
        dotenv_file = environments.PIPENV_DOTENV_LOCATION or os.sep.join(
            [project_directory, ".env"]
        )

        if os.path.isfile(dotenv_file):
            click.echo(
                crayons.normal(fix_utf8("Loading .env environment variables…"), bold=True),
                err=True,
            )
        else:
            if environments.PIPENV_DOTENV_LOCATION:
                click.echo(
                    "{0}: file {1}={2} does not exist!!\n{3}".format(
                        crayons.red("Warning", bold=True),
                        crayons.normal("PIPENV_DOTENV_LOCATION", bold=True),
                        crayons.normal(environments.PIPENV_DOTENV_LOCATION, bold=True),
                        crayons.red("Not loading environment variables.", bold=True),
                    ),
                    err=True,
                )
        dotenv.load_dotenv(dotenv_file, override=True)