Add drone support

.drone.yml

@@ -0,0 +1,19 @@
+kind: pipeline
+name: default
+
+steps:
+- name: test
+  image: debian:buster
+  commands:
+  - apt-get update -y
+  - apt-get install -y locales openjdk-11-jre python3-pip
+  - sed -e 's|^# es_ES.UTF-8 UTF-8|es_ES.UTF-8 UTF-8|g' -i /etc/locale.gen
+  - sed -e 's|^# en_US.UTF-8 UTF-8|en_US.UTF-8 UTF-8|g' -i /etc/locale.gen
+  - sed -e 's|^# eo.UTF-8 UTF-8|eo.UTF-8 UTF-8|g' -i /etc/locale.gen
+  - sed -e 's|^# fr_FR.UTF-8 UTF-8|fr_FR.UTF-8 UTF-8|g' -i /etc/locale.gen
+  - dpkg-reconfigure --frontend=noninteractive locales
+  - pip3 install babel beautifulsoup4 html5validator markdown pelican
+  - export LANG=es_ES.UTF-8 LANGUAGE=es_ES
+  - (cd cl-theme/ && make compile)
+  - cp -v Makefile.example Makefile
+  - make validate