Enable reproducible builds (#300)

https://maven.apache.org/guides/mini/guide-reproducible-builds.html
https://reproducible-builds.org/

Refs #299

Author: joschi

pom.xml

@@ -75,6 +75,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <project.build.outputTimestamp>2017-12-12T00:39:30Z</project.build.outputTimestamp>
         <project.scm.id>github</project.scm.id>
 
         <sonar.organization>openapitools</sonar.organization>
@@ -240,6 +241,7 @@
                             <notree>true</notree>
                             <nocomment>true</nocomment>
                             <nohelp>true</nohelp>
+                            <notimestamp>true</notimestamp>
                         </configuration>
                         <executions>
                             <execution>
@@ -267,6 +269,11 @@
                     <artifactId>maven-source-plugin</artifactId>
                     <version>3.2.1</version>
                 </plugin>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-jar-plugin</artifactId>
+                    <version>3.2.0</version>
+                </plugin>
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-release-plugin</artifactId>