initial tribeOS bidder adapter commit

[adnanmiljkovic]

Type of change

• Bugfix
• Feature
• New bidder adapter
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Does this change affect user-facing APIs or examples documented on http://prebid.org?
• Other

Description of change

• test parameters for validating bids

{
    bidder: "tribeos",
    params: {
        placementId: '12345' // REQUIRED
    }
}

• contact email of the adapter’s maintainer dev@tribeos.io
• official adapter submission
• Link to the PR on the docs repo initial tribeOS bidder adapter doc commit prebid.github.io#1755

[GLStephen]

LGTM - circle ci failure is unrelated, build locally and tests fine