Add credentials to dependency XML

### [REQUIRED] Please fill in the following fields:

* Unity editor version:All
* External Dependency Manager version:All
* Source you installed EDM4U: unitypackage
* Features in External Dependency Manager in use:Android Resolver,
* Plugins SDK in use: None
* Platform you are using the Unity editor on:MAC

### [REQUIRED] Please describe the question here:
Is there is a way to add to the Dependency.xml credentials like :
maven {
credentials {
username = 'username'
password = 'password'
}
url 'https://private-maven.com'
authentication {
basic(BasicAuthentication)
}
}

This is for our internal testing
Thanks