Not reading anything from .env file

Describe the bug When running theme watch and other commands, it doesn't read anything from the .env file.

To Reproduce Steps to reproduce the behavior:

1. Create a .env file in the root of your project

THEMEKIT_PASSWORD=shppa_SOMEPASSWORD
THEMEKIT_STORE=john-doe.myshopify.com
THEMEKIT_THEME_ID=123456789

2. Create a config.yml file in the root of your project
3. run command theme watch

This produces the following error:

invalid environment [development]: (missing theme_id,missing store domain,missing password)

Expected behavior Expect to start running on environment from .env file.

Environment (please complete the following information):

• OS [e.g. iOS]: macOS Big Sur 11.4
• Themekit version (run theme version to check): ThemeKit 1.3.0 darwin/amd64