Exclude commons-logging dependency from rdf-resource-resolver-core (#805)

This prevents the warning "Standard Commons Logging discovery in action with spring-jcl: please remove commons-logging.jar from classpath in order to avoid potential conflicts"

* exclude commons-logging dependency from rdf-resource-resolver-core
* add comments in pom with reason for exclusion

Author: dennisvang

pom.xml

@@ -85,6 +85,13 @@
             <groupId>org.fairdatateam.rdf</groupId>
             <artifactId>rdf-resource-resolver-core</artifactId>
             <version>${rdf-resolver.version}</version>
+            <exclusions>
+                <exclusion>
+                    <!-- excluded to avoid potential conflict w.r.t. Standard Commons Logging discovery and spring-jcl -->
+                    <groupId>commons-logging</groupId>
+                    <artifactId>commons-logging</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
         <dependency>
             <groupId>org.fairdatateam.rdf</groupId>
@@ -100,6 +107,7 @@
             <artifactId>spring-boot-starter-web</artifactId>
             <exclusions>
                 <exclusion>
+                    <!-- excluded because we're using spring-boot-starter-log4j2 instead (see spring-boot logging docs) -->
                     <groupId>org.springframework.boot</groupId>
                     <artifactId>spring-boot-starter-logging</artifactId>
                 </exclusion>