transcode: update profile name for rendition that matches the source

stream's resolution

Remote B (via access-token) rejects transcode request if a profile with
name "source" is used. The "source" keyword is used to define an
incoming RTMP push in go-livepeer (server/mediaserver.go) - which
triggers a different use-case. Change the profile name to follow the
name syntax (e.g. 720p) being used for the other profiles.

transcode/transcode.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"net/url"
 	"path"
+	"strconv"
 	"sync"
 	"time"
 
@@ -270,7 +271,7 @@ func getPlaybackProfiles(iv clients.InputVideo) ([]clients.EncodedProfile, error
 		profiles = []clients.EncodedProfile{lowBitrateProfile(video)}
 	}
 	profiles = append(profiles, clients.EncodedProfile{
-		Name:    "source",
+		Name:    strconv.FormatInt(int64(video.Height), 10) + "p0",
 		Bitrate: video.Bitrate,
 		FPS:     0,
 		Width:   video.Width,