make auth provider configurable

Author: fjakobs

lib/DBSQLClient.ts

@@ -84,12 +84,13 @@ export default class DBSQLClient extends EventEmitter implements IDBSQLClient {
    * Connects DBSQLClient to endpoint
    * @public
    * @param options - host, path, and token are required
+   * @param authProvider - Optional custom authentication provider
    * @returns Session object that can be used to execute statements
    * @example
    * const session = client.connect({host, path, token});
    */
-  async connect(options: ConnectionOptions): Promise<IDBSQLClient> {
-    this.authProvider = new PlainHttpAuthentication({
+  async connect(options: ConnectionOptions, authProvider?: IAuthentication): Promise<IDBSQLClient> {
+    this.authProvider = authProvider || new PlainHttpAuthentication({
       username: 'token',
       password: options.token,
       headers: {