chore: regenerate README (#340)

This PR was generated using Autosynth. 🌈


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

```
2021-02-05 05:30:21,103 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-webrisk/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-02-05 05:30:22,002 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/eb473351-17d5-4ae9-aa98-43f415ce3853/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-webrisk.git",
-        "sha": "88af38d0ec62c4be8d1d2ae9b79ed41290eb7ed6"
+        "sha": "773b436a3b787520a06867577b174a37f1e1dbd4"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "b259489b06b25f399768b74b8baa943991f38ea7"
+        "sha": "692715c0f23a7bb3bfbbaa300f7620ddfa8c47e5"
       }
     }
   ]

README.md

@@ -51,12 +51,12 @@ compile 'com.google.cloud:google-cloud-webrisk'
 ```
 If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-webrisk:1.1.7'
+compile 'com.google.cloud:google-cloud-webrisk:1.1.8'
 ```
 
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-webrisk" % "1.1.7"
+libraryDependencies += "com.google.cloud" % "google-cloud-webrisk" % "1.1.8"
 ```
 
 ## Authentication