[skip ci] removed ubuntu 16.04

.gitlab-ci.yml

@@ -111,7 +111,7 @@ stages:
 ############ LICENSE HEADERS ############
 license_headers:
   stage: license
-  image: labrobotica/wolf_deps:16.04
+  image: labrobotica/wolf_deps:20.04
   cache:
     - key: wolf-xenial
       paths:
@@ -124,27 +124,6 @@ license_headers:
   script:
     - *license_header_definition
 
-############ UBUNTU 16.04 TESTS ############
-build_and_test:xenial:
-  image: labrobotica/wolf_deps:16.04
-  stage: build_and_test
-  cache:
-    - key: wolf-xenial
-      paths:
-      - ci_deps/wolf/
-    - key: imu-xenial
-      paths:
-      - ci_deps/imu/
-  except:
-    - master
-  before_script:
-    - *preliminaries_definition
-    - *install_wolf_definition
-    - *install_wolfimu_definition
-    - ldconfig # update links (shared libraries)
-  script:
-    - *build_and_test_definition
-
 ############ UBUNTU 18.04 TESTS ############
 build_and_test:bionic:
   image: labrobotica/wolf_deps:18.04