build(deps): bump maven-source-plugin from 2.4 to 3.2.1 (#85)

Author: dependabot[bot]

pom.xml

@@ -64,7 +64,7 @@
         <cobertura-maven-plugin.version>2.7</cobertura-maven-plugin.version>
         <nexus-staging-maven-plugin.version>1.6.8</nexus-staging-maven-plugin.version>
         <maven-javadoc-plugin.version>3.2.0</maven-javadoc-plugin.version>
-        <maven-source-plugin.version>2.4</maven-source-plugin.version>
+        <maven-source-plugin.version>3.2.1</maven-source-plugin.version>
         <maven-gpg-plugin.version>1.6</maven-gpg-plugin.version>
         <junit-jupiter.version>5.6.2</junit-jupiter.version>
     </properties>