chore: regenerate README (#256)

This PR was generated using Autosynth. 🌈


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

```
2020-12-03 00:29:16,061 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-logging-logback/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2020-12-03 00:29:17,079 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/760ea8d9-9d5b-4449-91c9-b6d1c28ff25c/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-logging-logback.git",
-        "sha": "31b35b14aab4844d58f9550a38262e99edde0ba0"
+        "sha": "45e357611b40d5e7dd33dab91ef1548b1c47bfd9"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "7db8a6c5ffb12a6e4c2f799c18f00f7f3d60e279"
+        "sha": "f94318521f63085b9ccb43d42af89f153fb39f15"
       }
     }
   ]

README.md

@@ -20,17 +20,17 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-logging-logback</artifactId>
-  <version>0.118.5-alpha</version>
+  <version>0.118.7-alpha</version>
 </dependency>
 ```
 
 If you are using Gradle, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-logging-logback:0.118.5-alpha'
+compile 'com.google.cloud:google-cloud-logging-logback:0.118.7-alpha'
 ```
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-logging-logback" % "0.118.5-alpha"
+libraryDependencies += "com.google.cloud" % "google-cloud-logging-logback" % "0.118.7-alpha"
 ```
 
 ## Authentication