md-select not applying data- prefixed md-container-class

[vparusheva]

I have an md-select that I want to have a certain class applied to.
If I use md-container-class, it works all right, but if I use data-md-container-class instead, the class is not applied.
Using angular material 1.0.4 (current latest).

[devversion]

@vparusheva Fixed in #6976