Fix the client opts in the browser

Both `externalUserId` and `tokenCallback` are mandatory fields when
initializing the client in the browser. The SDK currently throws a
runtime error when they are not provided, so the type definition of
the client opts should reflect this requirement.

Author: jverce

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@pipedream/sdk",
-    "version": "2.0.1",
+    "version": "2.0.2",
     "private": false,
     "repository": "github:PipedreamHQ/pipedream-sdk-typescript",
     "type": "commonjs",

src/browser/index.ts

@@ -33,12 +33,12 @@ export type PipedreamClientOpts = Omit<BackendClientOpts, "clientId" | "clientSe
      * The callback function should return the response from
      * `serverClient.tokens.create`.
      */
-    tokenCallback?: TokenCallback;
+    tokenCallback: TokenCallback;
 
     /**
      * An external user ID associated with the token.
      */
-    externalUserId?: string;
+    externalUserId: string;
 };
 
 /**