Get rid of `backoff` dependency
Fix some types

Refs #24.
Fix: Proper connection error handling in init
Add `{registered, []}` to `.app.src` to avoid rebar bugs
Add `execute` debug logging
Only extract frame length once

Fix for retrieving large blobs.
Update Travis' otp_releases
Bump version to 0.1.7.
Return name and query when erlcql_client:prepare/3 fails

Fixes #26