chore: regenerate README (#466)

This PR was generated using Autosynth. 🌈


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

```
2021-03-15 15:30:30,092 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-dlp/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-03-15 15:30:31,115 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/ac377cbd-8146-4d9d-9d94-a33002b915e8/targets

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-dlp.git",
-        "sha": "49a994236960583f4d67977a8518690ba92ca6ee"
+        "sha": "ed71093afb189de12e5f172c8227d45f8abb56fa"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "2e7bd5cc66a3f0b90ce1c150eb35c89eeb9872d6"
+        "sha": "2c54c473779ea731128cea61a3a6c975a08a5378"
       }
     }
   ]

README.md

@@ -52,12 +52,12 @@ compile 'com.google.cloud:google-cloud-dlp'
 ```
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-dlp:2.2.9'
+compile 'com.google.cloud:google-cloud-dlp:2.3.0'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-dlp" % "2.2.9"
+libraryDependencies += "com.google.cloud" % "google-cloud-dlp" % "2.3.0"
 ```
 
 ## Authentication