Migrates from maven to gradle for building and fixes the package names.

tools/bash/build-plugin.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+set -e
+
+# Find project root (two directories above this script)
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
+
+cd "$PROJECT_ROOT"
+
+./gradlew build