moved all dependencies version to main pom.xml

dhp-workflows/dhp-doiboost/pom.xml

@@ -14,7 +14,7 @@
             <plugin>
                 <groupId>net.alchim31.maven</groupId>
                 <artifactId>scala-maven-plugin</artifactId>
-                <version>4.0.1</version>
+                <version>${net.alchim31.maven.version}</version>
                 <executions>
                     <execution>
                         <id>scala-compile-first</id>
@@ -51,7 +51,7 @@
         <dependency>
             <groupId>org.apache.httpcomponents</groupId>
             <artifactId>httpclient</artifactId>
-            <version>4.3.4</version>
+            <version>${org.apache.httpcomponents.version}</version>
         </dependency>
         <dependency>
             <groupId>eu.dnetlib.dhp</groupId>

pom.xml

@@ -670,5 +670,7 @@
 		<json4s.version>3.5.3</json4s.version>
 		<jsonschemagenerator.version>4.13.0</jsonschemagenerator.version>
 		<common.text.version>1.8</common.text.version>
+		<org.apache.httpcomponents.version>4.3.4</org.apache.httpcomponents.version>
+		<net.alchim31.maven.version>4.0.1</net.alchim31.maven.version>
 	</properties>
 </project>