chore: regenerate README (#412)

This PR was generated using Autosynth. 🌈


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

```
2021-05-19 03:37:37,485 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigqueryconnection/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-05-19 03:37:38,667 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/c010e3e0-cd0c-46c6-824e-53c953415aab/targets

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigqueryconnection.git",
-        "sha": "baa7fe9b4bba2f4b9532ae3108ea61db4f91c91b"
+        "sha": "2b43cd30924ced9f4fa79baa8311fa69a13414b7"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "4f4b1b9b8d8b52f1e9e4a76165896debce5ab7f1"
+        "sha": "7332178a11ddddc91188dc0f25bca1ccadcaa6c6"
       }
     }
   ]

README.md

@@ -17,19 +17,19 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-bigqueryconnection</artifactId>
-  <version>1.0.17</version>
+  <version>1.0.18</version>
 </dependency>
 
 ```
 
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-bigqueryconnection:1.0.17'
+compile 'com.google.cloud:google-cloud-bigqueryconnection:1.0.18'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-bigqueryconnection" % "1.0.17"
+libraryDependencies += "com.google.cloud" % "google-cloud-bigqueryconnection" % "1.0.18"
 ```
 
 ## Authentication