wip
AppNexus: Add API client methods for pixels
Merge branch 'master' into TSPixel
Merge branch 'master' of https://github.com/RareCrowds/OpenAdStack into TSPixel
TS: Traveltorial pixels (WiP)
AppNexus: Add attributed conversions report request to AppNexus API Client
Merge branch 'master' into TSPixel
AppNexus: Add base64 entity ids to line-item and campaign codes
 * Pulled from ${CPG_CODE} and ${CP_CODE} by Traveltorial renderer for use in conversion pixel data
 * Note: due to AppNexus code character restrictions '+' is replaced with '-' and '/' with '_'.
 * Also add CampaignEntity.ExternalEntityId to line-item names
    - Avoids an extra look-up when parsing Attributed Conversion reports
AppNexus: Traveltorial v1.1
 * Defined as ad type TravelSpikeTraveltorial11 for now (will replace TravelSpikeTraveltorial later)
 * Uses conversion pixels in place of click trackers
 * Retains compatibility with v1.0 Traveltorial template
 * Adds AppNexus.PixelUri to configurations