make sure, .tar.gz is built on travis

main/ant-kit/pom.xml

@@ -73,6 +73,15 @@
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<id>make-assembly</id>
+						<phase>package</phase>
+						<goals>
+							<goal>single</goal>
+						</goals>
+					</execution>
+				</executions>
 				<configuration>
 					<descriptor>assembly.xml</descriptor>
 					<finalName>cryptomator_${project.version}</finalName>