fix: upgrade com.google.code.gson:gson from 2.8.7 to 2.8.8

Snyk has created this PR to upgrade com.google.code.gson:gson from 2.8.7 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/mariazevedo88/project/ba7bef0d-75c8-42b5-8200-e2c1d502576b?utm_source=github&utm_medium=upgrade-pr

pom.xml

@@ -30,7 +30,7 @@
 
 		<java.version>1.8</java.version>
 
-		<gson.version>2.8.7</gson.version>
+		<gson.version>2.8.8</gson.version>
 		<log4j.version>1.2.17</log4j.version>
 		<junit.jupiter.version>5.5.1</junit.jupiter.version>
 		<jacoco.version>0.8.4</jacoco.version>