chore: regenerate README (#222)

This PR was generated using Autosynth. 🌈 <details><summary>Log from Synthtool</summary> ``` 2020-10-16 00:17:05,710 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-billing/.github/readme/synth.py. On branch autosynth-readme nothing to commit, working directory clean 2020-10-16 00:17:06,717 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/d31fe428-8d25-4e96-8ba3-0e23342e35c7/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-billing.git",
- "sha": "7505af43959105d5d5a8ff0ab99b1cc66caa5886"
+ "sha": "2e92a1ee08ec9dd8c86ac852f8a654beaef113f0"
  }
  },
  {
  "git": {
  "name": "synthtool",
  "remote": "https://github.com/googleapis/synthtool.git",
- "sha": "27e0e916cbfdb3d5ff6639b686cc04f78a0b0386"
+ "sha": "7c5370937dd9ba9dcf9cd7d2af880a58b389b4f1"
  }
  }
  ]

README.md

@@ -17,7 +17,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file
  <dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>libraries-bom</artifactId>
- <version>12.0.0</version>
+ <version>12.1.0</version>
  <type>pom</type>
  <scope>import</scope>
  </dependency>