chore: regenerate README (#400)

This PR was generated using Autosynth. 🌈


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

```
2020-12-14 20:04:48,139 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-dataproc/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2020-12-14 20:04:49,105 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/24e2f765-662c-4fcc-89c0-f0608f3d3f13/targets

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

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

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-dataproc.git",
-        "sha": "4fac03735c5044ea07d22db640d4eee094b3d305"
+        "sha": "bfd2e191598235e3a1ab36a9a35e1949504b5a54"
       }
     },
     {

README.md

@@ -39,7 +39,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-dataproc</artifactId>
-  <version>1.1.7</version>
+  <version>1.1.8</version>
 </dependency>
 
 ```