Remove Ubuntu Xenial packages

Connects to archivematica/Issues#1451.

.Jenkinsci

@@ -62,14 +62,4 @@ node {
       string(name: 'REPOSITORY', value: "${REPOSITORY}")]
   }
 
-  stage('Build xenial packages') {
-    build job: 'am-packbuild/xenial-jenkinsci', parameters: [
-      string(name: 'PACKAGE', value: "${PACKAGE}"),
-      string(name: 'BRANCH', value: 'qa/1.x'),
-      string(name: 'GPG_ID', value: '0F4A4D31'),
-      string(name: 'VERSION', value: "${VERSION}"),
-      string(name: 'RELEASE', value: "${RELEASE}"),
-      string(name: 'REPOSITORY', value: "${REPOSITORY}")]
-  }
-
 }

.Jenkinsci-ss

@@ -62,14 +62,4 @@ node {
       string(name: 'REPOSITORY', value: "${REPOSITORY}")]
   }
 
-  stage('Build xenial packages') {
-    build job: 'am-packbuild/xenial-jenkinsci', parameters: [
-      string(name: 'PACKAGE', value: "${PACKAGE}"),
-      string(name: 'BRANCH', value: 'qa/0.x'),
-      string(name: 'GPG_ID', value: '0F4A4D31'),
-      string(name: 'VERSION', value: "${VERSION}"),
-      string(name: 'RELEASE', value: "${RELEASE}"),
-      string(name: 'REPOSITORY', value: "${REPOSITORY}")]
-  }
-
 }

README.md

@@ -8,11 +8,11 @@ CentOS 7 packages:
 
 This also builds a local repository that you can use later from `rpm-testing`.
 
-We don't have a single target yet for Xenial/Trusty packages but you can build
-the packages individually, for example:
+We don't have a single target yet for Debian packages but you can build them
+individually, for example:
 
-    make -C debs/xenial/archivematica
-    make -C debs/xenial/archivematica-storage-service
+    make -C debs/bionic/archivematica
+    make -C debs/bionic/archivematica-storage-service
 
 #### Using parameters