sweet: remove sweet get -auth flag from README

Authentication is not required to download assets.

Change-Id: Ia2ba4a2acd57c40254026974b2c6eac35a5e0e61
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/449176
Auto-Submit: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
diff --git a/sweet/README.md b/sweet/README.md
index 6545c9b..0ce6560 100644
--- a/sweet/README.md
+++ b/sweet/README.md
@@ -54,14 +54,9 @@
 ### Getting Assets
 
 ```sh
-$ ./sweet get -auth=app-default
+$ ./sweet get
 ```
 
-Note: make sure you run `gcloud auth application-default login` before you run
-the above command! 
-
-TODO(mknyszek): Make it so authentication isn't necessary in the future.
-
 ### Running the benchmarks
 
 Create a configuration file called `config.toml` with the following contents: