Add docker support

docker-ledger/src/ratpack/Ratpack.groovy

@@ -0,0 +1,24 @@
+import com.devsoap.dbt.DBTModule
+import org.h2.jdbcx.JdbcDataSource
+import org.slf4j.LoggerFactory
+
+import javax.sql.DataSource
+
+import static ratpack.groovy.Groovy.ratpack
+
+def log = LoggerFactory.getLogger('dbt-executor')
+
+ratpack {
+    serverConfig {
+        env()
+        sysProps()
+    }
+
+    bindings {
+        bindInstance(DataSource, new JdbcDataSource(url: 'jdbc:h2:mem:dbtdb;DB_CLOSE_DELAY=-1', user: ''))
+        module (DBTModule)  { config ->
+            log.info "Executor available at $config.executor.remoteUrl"
+            log.info "Ledger available at $config.ledger.remoteUrl"
+        }
+    }
+}