chore: regenerate README (#280)

This PR was generated using Autosynth. 🌈


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

```
2020-11-02 18:21:35,238 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-websecurityscanner/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working directory clean
2020-11-02 18:21:36,191 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/a390e26b-5cfd-4b0f-9436-65d46b9b0cd8/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-websecurityscanner.git",
-        "sha": "eb21b189f6345398b4ca1f151d49738f1f6c4517"
+        "sha": "d0a26309d46e7b67e05404ccf035cc38e830af6c"
       }
     },
     {

README.md

@@ -38,7 +38,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-websecurityscanner</artifactId>
-  <version>1.0.3</version>
+  <version>1.0.4</version>
 </dependency>
 
 ```