chore: regenerate README (#998)

This PR was generated using Autosynth. 🌈


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

```
2020-12-05 00:16:21,423 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquery/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2020-12-05 00:16:22,330 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/63af523f-a9a8-4c04-a925-63f6b4b2c546/targets

- [ ] To automatically regenerate this PR, check this box.

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquery.git",
-        "sha": "cf36b82ef9bc0849a87b717c099321915a76b967"
+        "sha": "6de06aa721d63a8f4972cfcec6afa4ec5b068bc9"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "c2de32114ec484aa708d32012d1fa8d75232daf5"
+        "sha": "18c5dbdb4ac8cf75d4d8174e7b4558f48e76f8a1"
       }
     }
   ]

README.md

@@ -40,18 +40,18 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigquery</artifactId>
-  <version>1.125.0</version>
+  <version>1.125.2</version>
 </dependency>
 
 ```
 
 If you are using Gradle, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-bigquery:1.125.0'
+compile 'com.google.cloud:google-cloud-bigquery:1.125.2'
 ```
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-bigquery" % "1.125.0"
+libraryDependencies += "com.google.cloud" % "google-cloud-bigquery" % "1.125.2"
 ```
 
 ## Authentication