chore: regenerate README (#343)

This PR was generated using Autosynth. 🌈


<details><summary>Log from Synthtool</summary>

```
2020-10-27 20:40:30,882 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-pubsublite/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working directory clean
2020-10-27 20:40:31,830 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

```
</details>

Full log will be available here:
https://source.cloud.google.com/results/invocations/70ebbd0a-8326-4d06-834c-611abdf5fb77/targets

- [ ] To automatically regenerate this PR, check this box.

Author: yoshi-automation

.github/readme/synth.metadata/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-pubsublite.git",
-        "sha": "715f58a170cbf8ca5a825eeeb71dee57e569358f"
+        "sha": "5d7e95e3cc5a9b145a7686cbed8aaaeec88290e4"
       }
     },
     {

README.md

@@ -20,7 +20,7 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-pubsublite</artifactId>
-  <version>0.6.0</version>
+  <version>0.6.1</version>
 </dependency>
 <dependency>
   <groupId>com.google.cloud</groupId>