Remove guava dependency (#1776)

Signed-off-by: Marinov Avgustin <Avgustin.Marinov@bosch.com>

hawkbit-rest/hawkbit-ddi-api/pom.xml

@@ -54,6 +54,11 @@
          <artifactId>spring-boot-starter-test</artifactId>
          <scope>test</scope>
       </dependency>
+      <dependency>
+         <groupId>io.github.classgraph</groupId>
+         <artifactId>classgraph</artifactId>
+         <scope>test</scope>
+      </dependency>
       <dependency>
          <groupId>org.assertj</groupId>
          <artifactId>assertj-core</artifactId>