chore: regenerate README (#688)

This PR was generated using Autosynth. 🌈


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

```
2021-03-10 19:56:00,267 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquerydatatransfer/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-03-10 19:56:01,251 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/30ed5cc3-35ba-42e6-b999-b7d645a480c9/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-bigquerydatatransfer.git",
-        "sha": "6a541d7ea9dc95ba5eb0d1ce4736307ef096ff24"
+        "sha": "6b10b971ff8f58899d02f392918f59e5984d67db"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "e5fa6d93e42918dd4a000a80b92be23f5f4c6ac7"
+        "sha": "0b064d767537e0675fc053e53fca473c5c701fb8"
       }
     }
   ]

README.md

@@ -38,7 +38,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigquerydatatransfer</artifactId>
-  <version>1.1.2</version>
+  <version>1.2.0</version>
 </dependency>
 
 ```