Move nightly builds to Travis CI

This updates previous work in #739 to build
Debian packages and zip files for other OS.

All the build artifacts are uploaded to S3
public bucket `aptly-nightly` so that there's
archive for all the builds.

All `.deb` packages are automatically uploaded
to repo.aptly.info/nightly on build.

upload-artifacts.sh

@@ -0,0 +1,35 @@
+#!/bin/sh
+
+set -e
+
+builds=build/
+packages=${builds}*.deb
+folder=`mktemp -u tmp.XXXXXXXXXXXXXXX`
+aptly_user="$APTLY_USER"
+aptly_password="$APTLY_PASSWORD"
+aptly_api="https://internal.aptly.info"
+
+for file in $packages; do
+    echo "Uploading $file..."
+    curl -sS -X POST -F "file=@$file" -u $aptly_user:$aptly_password ${aptly_api}/api/files/$folder
+    echo
+done
+
+if [[ "$1" = "nightly" ]]; then
+    aptly_repository=aptly-nightly
+    aptly_published=s3:repo.aptly.info:./nightly
+
+    echo "Adding packages to $aptly_repository..."
+    curl -sS -X POST -u $aptly_user:$aptly_password ${aptly_api}/api/repos/$aptly_repository/file/$folder
+    echo
+
+    echo "Updating published repo..."
+    curl -sS -X PUT -H 'Content-Type: application/json' --data \
+        '{"AcquireByHash": true, "Signing": {"Batch": true, "Keyring": "aptly.repo/aptly.pub",
+                                             "secretKeyring": "aptly.repo/aptly.sec", "PassphraseFile": "aptly.repo/passphrase"}}' \
+        -u $aptly_user:$aptly_password ${aptly_api}/api/publish/$aptly_published
+    echo
+fi
+
+curl -sS -X DELETE  -u $aptly_user:$aptly_password ${aptly_api}/api/files/$folder
+echo