feat(include): Remove include key in tasks

Author: yyoshiki41

tasks/main.yml

@@ -1,5 +1,5 @@
 ---
 
-- include: python.yml
+- import_tasks: python.yml
   when: python_enabled
   tags: [python]

tasks/python.yml

@@ -1,9 +1,9 @@
 ---
 
-- include: install.deb.yml
+- import_tasks: install.deb.yml
   when: ansible_os_family == 'Debian'
 
-- include: install.yum.yml
+- import_tasks: install.yum.yml
   when: ansible_os_family == 'RedHat'
 
 - file: state=directory name=/usr/share/python

test.yml

@@ -1,6 +1,6 @@
 - hosts: all
   tasks:
-    - include: tasks/main.yml
+    - import_tasks: tasks/main.yml
   vars_files:
     - defaults/main.yml
     - .travis.yml