chore: regenerate README (#93)

This PR was generated using Autosynth. 🌈


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

```
2021-06-25 16:13:43,223 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-networkconnectivity/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-06-25 16:13:44,363 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/e8226e37-6376-410e-875d-ed30b3a0a23d/targets

- [ ] To automatically regenerate this PR, check this box. (May take up to 24 hours.)

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-networkconnectivity.git",
-        "sha": "60956446e32721f336de0adc1e42eb8efd3dd130"
+        "sha": "15090cdacf44848cedffd63b6e08e10b464cf917"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "ff6b759fcb58f216f62b48d5be0bb85fafbc3bb2"
+        "sha": "26558bae8976a985d73c2d98c31d8612273f907d"
       }
     }
   ]

README.md

@@ -20,19 +20,19 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-networkconnectivity</artifactId>
-  <version>0.2.3</version>
+  <version>0.3.0</version>
 </dependency>
 
 ```
 
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-networkconnectivity:0.2.3'
+compile 'com.google.cloud:google-cloud-networkconnectivity:0.3.0'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-networkconnectivity" % "0.2.3"
+libraryDependencies += "com.google.cloud" % "google-cloud-networkconnectivity" % "0.3.0"
 ```
 
 ## Authentication