chore: regenerate README (#278)

This PR was generated using Autosynth. 🌈


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

```
2021-01-07 16:22:48,059 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigqueryconnection/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-01-07 16:22:48,917 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/b66ab122-fb9a-4eaf-b168-2d2b3ac4a90d/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-bigqueryconnection.git",
-        "sha": "8352cdf63c660591cb02808c313c7431f1bab659"
+        "sha": "fc71f91e966dbb279b8c0dc9f899c3bb05b2bd4d"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "3f67ceece7e797a5736a25488aae35405649b90b"
+        "sha": "a3e990f3545dc8ccd384a75d20ce9cb185ca6a28"
       }
     }
   ]

README.md

@@ -22,10 +22,11 @@ If you are using Maven, add this to your pom.xml file:
 
 ```
 
-If you are using Gradle, add this to your dependencies
+If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
 compile 'com.google.cloud:google-cloud-bigqueryconnection:1.0.6'
 ```
+
 If you are using SBT, add this to your dependencies
 ```Scala
 libraryDependencies += "com.google.cloud" % "google-cloud-bigqueryconnection" % "1.0.6"