Updates maven dependencies and cleans POM

* spring-boot
* springframework
* Apache Camel
* JUnit

pom.xml

@@ -27,54 +27,49 @@
  <type>pom</type>
  <scope>import</scope>
  </dependency>
+ <dependency>
+ <groupId>org.apache.camel</groupId>
+ <artifactId>camel-bom</artifactId>
+ <version>${camel.version}</version>
+ <type>pom</type>
+ <scope>import</scope>
+ </dependency>
  </dependencies>
  </dependencyManagement>
  <dependencies>
  <dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
- <version>4.12</version>
+ <version>4.13.1</version>
  <scope>test</scope>
  </dependency>
- <dependency>
- <groupId>log4j</groupId>
- <artifactId>log4j</artifactId>
- <version>1.2.17</version>
- </dependency>
  <dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-log4j12</artifactId>
- <version>1.7.5</version>
  </dependency>
  <dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-spring</artifactId>
- <version>${camel.version}</version>
  </dependency>
  <dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-core</artifactId>
- <version>${camel.version}</version>
  </dependency>
  <dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-servlet</artifactId>
- <version>${camel.version}</version>
  </dependency>
  <dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-sql</artifactId>
- <version>${camel.version}</version>
  </dependency>
  <dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-jaxb</artifactId>
- <version>${camel.version}</version>
  </dependency>
  <dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-http</artifactId>
- <version>${camel.version}</version>
  </dependency>
  <dependency>
  <groupId>org.springframework</groupId>
@@ -104,21 +99,12 @@
  <!-- Explicitly add JAXB dependencies. Needed for newer Java versions.
  See also https://stackoverflow.com/questions/43574426/how-to-resolve-java-lang-noclassdeffounderror-javax-xml-bind-jaxbexception-in-j
  -->
+ <!-- JAXB version corresponding to version used in Apache Camel -->
  <dependency>
  <groupId>javax.xml.bind</groupId>
  <artifactId>jaxb-api</artifactId>
  <version>${jaxb.version}</version>
  </dependency>
- <dependency>
- <groupId>com.sun.xml.bind</groupId>
- <artifactId>jaxb-core</artifactId>
- <version>${jaxb.version}</version>
- </dependency>
- <dependency>
- <groupId>com.sun.xml.bind</groupId>
- <artifactId>jaxb-impl</artifactId>
- <version>${jaxb.version}</version>
- </dependency>
  <dependency>
  <groupId>javax.activation</groupId>
  <artifactId>activation</artifactId>
@@ -237,10 +223,10 @@
  </pluginManagement>
  </build>
  <properties>
- <camel.version>2.24.0</camel.version>
+ <camel.version>2.24.3</camel.version>
  <jaxb.version>2.3.0</jaxb.version>
- <spring.version>5.1.6.RELEASE</spring.version>
- <spring-boot.version>2.1.4.RELEASE</spring-boot.version>
+ <spring.version>5.1.19.RELEASE</spring.version>
+ <spring-boot.version>2.1.18.RELEASE</spring-boot.version>
  <spring-framework.version>${spring.version}</spring-framework.version>
 
  <oai-pmh.base.url.external>http:https://localhost:8080/omdf</oai-pmh.base.url.external>