Implemented CI/CD pipeline for automatic MR builds (but not tests yet)

Bumped version of build plugins to latest
Increased maven build heap size to 1024m as builds were starting to run out of memory
Added missing version number to build plugin, fixes build warning

.gitlab-ci.yml

@@ -0,0 +1,25 @@
+variables:
+  # This will suppress any download for dependencies and plugins or upload messages which would clutter the console log.
+  # `showDateTime` will show the passed time in milliseconds. You need to specify `--batch-mode` to make this work.
+  MAVEN_OPTS: "-Dhttps.protocols=TLSv1.2 -Dmaven.repo.local=$CI_PROJECT_DIR/.m2/repository -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=WARN -Dorg.slf4j.simpleLogger.showDateTime=true -Djava.awt.headless=true -Xmx1024m"
+  # As of Maven 3.3.0 instead of this you may define these options in `.mvn/maven.config` so the same config is used
+  # when running from the command line.
+  MAVEN_CLI_OPTS: "--batch-mode --errors --fail-fast --show-version"
+
+# This template uses jdk8 for verifying and deploying images
+image: maven:3-openjdk-11
+
+# Cache downloaded dependencies and plugins between builds.
+# To keep cache across branches add 'key: "$CI_JOB_NAME"'
+cache:
+  paths:
+    - .m2/repository
+
+verify:jdk11:
+  stage: build
+  script:
+    - 'cd Server'
+    - 'mvn $MAVEN_CLI_OPTS verify -DskipTests'
+  except:
+    variables:
+      - $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH

Server/pom.xml

@@ -93,6 +93,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-install-plugin</artifactId>
+        <version>3.0.1</version>
         <executions>
           <execution>
             <id>install-consts</id>
@@ -132,7 +133,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-assembly-plugin</artifactId>
-        <version>3.1.1</version>
+        <version>3.4.2</version>
 
         <configuration>
           <descriptorRefs>
@@ -185,8 +186,9 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-compiler-plugin</artifactId>
-        <version>3.5.1</version>
+        <version>3.10.1</version>
         <configuration>
+          <maxmem>1024m</maxmem>
           <useIncrementalCompilation>false</useIncrementalCompilation>
         </configuration>
         <executions>