chore: regenerate README (#170)

This PR was generated using Autosynth. 🌈


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

```
2021-01-11 19:39:53,117 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-workflows/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-01-11 19:39:54,001 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/f8e80532-a780-4e3c-a818-6eeda43edb54/targets

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java-workflows/.github/readme/synth.metadata/synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-workflows.git",
-        "sha": "c3a180955ebcf569caebece349fa2565f7ea0929"
+        "sha": "b4f48a07da5e155cffa991d40588dcaa6e9ef796"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "996775eca5fd934edac3c2ae34b80ff0395b1717"
+        "sha": "16ec872dd898d7de6e1822badfac32484b5d9031"
       }
     }
   ]

java-workflows/README.md

@@ -25,10 +25,11 @@ If you are using Maven, add this to your pom.xml file:
 
 ```
 
-If you are using Gradle, add this to your dependencies
+If you are using Gradle without BOM, add this to your dependencies
 ```Groovy
 compile 'com.google.cloud:google-cloud-workflows:0.1.4'
 ```
+
 If you are using SBT, add this to your dependencies
 ```Scala
 libraryDependencies += "com.google.cloud" % "google-cloud-workflows" % "0.1.4"