Improve logging response after submitting dependencies

[dancewithheart]

Fix #191

From my tests this:

sbt-dependency-submission/sbt-plugin/src/main/scala/ch/epfl/scala/SubmitDependencyGraph.scala

Line 117 in 190e840

state.log.info(s"Submitting dependency snapshot of job $job to $snapshotUrl")

looks in logs like this:

Submitting dependency snapshot of job ... to https://api.github.com/repos/dancewithheart/temporary-scala-vulns-watch/dependency-graph/snapshots

and is rendered by browser as URL but it is not valid URL (for GET requests) as it returns 404.

So I changed that to:

state.log.info(s"Submitting dependency snapshot of job $job to GitHub Dependency Graph API")

because later snapshotUrl/snapshotId is logged:

"submission-api-url" -> s"$snapshotUrl/$snapshotId"

and that is actually valid URL for sending GET requests :)

we should log the httpResp response body

added httpRespo to logs:

s"GitHub submission response: ${httpResp.bodyAsString}"

[tgodzik]

Thanks LGTM