Replace environement variable in a pre-commit

When I run run commits for the CLI the environment variable on my mac is properly replaced. But when I try to commit from SourceTree it fails, and I get this error message: 
```
husky > pre-commit (node v14.16.1)
Error: Failed to replace env in config: ${GITHUB_TOKEN}
```

An issue on the husky repo reports other users who experienced the same with Sourcetree. https://github.com/typicode/husky/issues/131. 
When I run commands from command line, or via VSCode or Inteelij it succeeds.