chore: regenerate README (#183)

This PR was generated using Autosynth. 🌈


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

```
2021-02-25 19:44:18,801 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-aiplatform/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-02-25 19:44:20,401 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/5bba306d-6693-405a-a760-f2c7c5fb350a/targets

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Author: yoshi-automation

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

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-aiplatform.git",
-        "sha": "f1523a2be87331d2298d740da041eb5275fb4813"
+        "sha": "43e69a4025d88eeaa80fb0341b76465baeb53367"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "79ab0b44a2cc7d803d07c107f9faf07729fc4012"
+        "sha": "8c5628b86cfa8386de7b8fc1675e6b528b552d57"
       }
     }
   ]

README.md

@@ -37,7 +37,7 @@ If you are using Maven without BOM, add this to your dependencies:
 
 If you are using Gradle 5.x or later, add this to your dependencies
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:17.0.0')
+implementation platform('com.google.cloud:libraries-bom:18.0.0')
 
 compile 'com.google.cloud:google-cloud-aiplatform'
 ```