Implements is not supported

[GillisWerrebrouck]

If a connection is between a class and an interface, the connection between them is compiled as an extension.

Example:

class A {
        + someProp string
        - someOtherProp number

        + number computeSomething(string x)
    }
interface B
A --|> B
@enduml```

Code:
```class A extends B {
  private string : someProp;
  private number : someOtherProp;
  computeSomething(x) {
    return;
  }
}

interface B {
}```

Expected:
```class A implements B {
  private string : someProp;
  private number : someOtherProp;
  computeSomething(x) {
    return;
  }
}

interface B {
}```

[bafolts]

This will require updating most of the templates. For languages like javascript that don't support interfaces the connection will be ignored.