authentication for private repositories

[rblazquez]

I have problems to configure a private repo because of "unauthorized: authentication required"

using plain docker i would do "docker login" and later push.

how can i perform this with the plugin?

[PatrickHuetter]

+1

[LiZhenchong]

+1

[fenske]

@mattgruter We need this :)

[laviua]

+1

[maksaimer]

+1

[Geniy00]

+1

[newrey]

+1