Remove Travis script, functionality is fully migrated to GitLab

Changelog: None

Signed-off-by: Lluis Campos <lluis.campos@northern.tech>

.travis.yml

@@ -1,17 +0,0 @@
-language: minimal
-
-# Disable git shallow clone. We need full history for validating copyright year of each file.
-git:
-    depth: false
-
-dist: trusty
-
-before_script:
-    - git clone git://github.com/mendersoftware/mendertesting
-
-script:
-    # Check commit compliance.
-    - mendertesting/check_commits.sh
-    # Check licenses
-    - mendertesting/check_license.sh
-    - ./docker-build