chore: regenerate README (#414)

This PR was generated using Autosynth. 🌈


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

```
2020-12-09 06:25:16,467 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-pubsublite/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2020-12-09 06:25:17,387 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/cb843c57-4908-4f6e-a528-360240ce1d19/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-pubsublite.git",
-        "sha": "9059c495d46765745bb5eb1d988412285ffd51ba"
+        "sha": "b745f58722a43ac9811d6eaaf8966423e4db6231"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "3559dd8cb634347737632776ef4089443eacdb4f"
+        "sha": "7d1ee3207371ef72a1ca931a0964c4007e687280"
       }
     }
   ]

README.md

@@ -32,11 +32,11 @@ If you are using Maven, add this to your pom.xml file:
 
 If you are using Gradle, add this to your dependencies
 ```Groovy
-compile 'com.google.cloud:google-cloud-pubsublite:0.6.5'
+compile 'com.google.cloud:google-cloud-pubsublite:0.7.0'
 ```
 If you are using SBT, add this to your dependencies
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-pubsublite" % "0.6.5"
+libraryDependencies += "com.google.cloud" % "google-cloud-pubsublite" % "0.7.0"
 ```
 
 ## Authentication