Version update of Tableschema lib; other dependency updates

Author: JohannesJander

pom.xml

@@ -17,7 +17,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <java.version>13</java.version>
+        <java.version>8</java.version>
         <maven.compiler.source>${java.version}</maven.compiler.source>
         <maven.compiler.target>${java.version}</maven.compiler.target>
         <tableschema-java-version>0.2.4</tableschema-java-version>