chore: regenerate README (#319)

This PR was generated using Autosynth. 🌈


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

```
2020-10-22 14:22:11,600 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-pubsublite/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working directory clean
2020-10-22 14:22:12,630 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/643fef1e-035b-41f7-8626-039d525fcd69/targets

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

Author: yoshi-automation

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-pubsublite.git",
-        "sha": "ed9d961aa7b79c18eb877a69203b042b0cebae86"
+        "sha": "7438bc8260d00f040d5026073fa0507115d0fce1"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "6abb59097be84599a1d6091fe534a49e5c5cf948"
+        "sha": "901ddd44e9ef7887ee681b9183bbdea99437fdcc"
       }
     }
   ]

README.md

@@ -20,12 +20,12 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-pubsublite</artifactId>
-  <version>0.4.1</version>
+  <version>0.5.0</version>
 </dependency>
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-pubsub</artifactId>
-  <version>1.108.4</version>
+  <version>1.108.5</version>
 </dependency>
 
 ```