fix: upgrade com.google.code.gson:gson from 2.8.5 to 2.8.8 (#684)

Snyk has created this PR to upgrade com.google.code.gson:gson from 2.8.5 to 2.8.8.

See this package in Maven Repository:
https://mvnrepository.com/artifact/com.google.code.gson/gson/

See this project in Snyk:
https://app.snyk.io/org/dogeared/project/76cafdc8-8c18-4705-9786-9703c2e293c9?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

pom.xml

@@ -76,7 +76,7 @@
 
         <jackson.version>2.12.5</jackson.version>
         <orgjson.version>20180130</orgjson.version>
-        <gson.version>2.8.5</gson.version>
+        <gson.version>2.8.8</gson.version>
 
         <!-- Optional Runtime Dependencies: -->
         <bouncycastle.version>1.60</bouncycastle.version>