ci: Lint package with ynh linter

.travis.yml

@@ -0,0 +1,8 @@
+language: php
+
+before_script:
+    - git clone --depth 1 git://github.com/YunoHost/package_linter ../package_linter && cd ../package_linter
+    - mv ../hostspot_ynh hostspot_ynh
+
+script:
+    - ./package_linter.py hostspot_ynh