build: increase spring version

oaipmh-core/pom.xml

@@ -95,6 +95,11 @@
 			<artifactId>spring-web</artifactId>
 			<version>${spring.version}</version>
 		</dependency>
+		<dependency>
+      <groupId>org.springframework</groupId>
+		  <artifactId>spring-context</artifactId>
+			<version>${spring.version}</version>
+		</dependency>
 		<!-- https://mvnrepository.com/artifact/com.thoughtworks.xstream/xstream -->
 		<dependency>
 			<groupId>com.thoughtworks.xstream</groupId>