chore: regenerate README (#34)

This PR was generated using Autosynth. 🌈


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

```
2021-04-16 15:32:28,527 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-artifact-registry/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-04-16 15:32:29,758 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/72843fe4-19b1-45c3-b199-de421216b288/targets

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

@@ -0,0 +1,18 @@
+{
+  "sources": [
+    {
+      "git": {
+        "name": ".",
+        "remote": "https://github.com/googleapis/java-artifact-registry.git",
+        "sha": "88a1ebd6b5f251813daeb08df68367bfb9f63cdd"
+      }
+    },
+    {
+      "git": {
+        "name": "synthtool",
+        "remote": "https://github.com/googleapis/synthtool.git",
+        "sha": "898b38a6f4fab89a76dfb152480bb034a781331b"
+      }
+    }
+  ]
+}

README.md

@@ -20,18 +20,18 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-artifact-registry</artifactId>
-  <version>0.0.0</version>
+  <version>0.1.2</version>
 </dependency>
 ```
 
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-artifact-registry:0.0.0'
+compile 'com.google.cloud:google-cloud-artifact-registry:0.1.2'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-artifact-registry" % "0.0.0"
+libraryDependencies += "com.google.cloud" % "google-cloud-artifact-registry" % "0.1.2"
 ```
 
 ## Authentication