Environment variables not work without config file

[diegoleme]

Describe the bug

When there is no configuration file (ex.: vite.config.ts), the environment variables of the .env files are not loaded.

This code snippet is not executed: https://github.com/vitejs/vite/blob/master/src/node/config.ts#L349

The configuration file is required?

Reproduction

https://github.com/recruto/cms

System Info

• vite: 0.17.2
• macOS: 10.15.4
• Node: 12.9.1
• yarn: 1.22.4
• vue version: 3.0.0-beta.14
• @vue/compiler-sfc: 3.0.0-beta.14