Improved composer update/install

Author: mblaschke

provision/roles/boilerplate-main/tasks/bootstrap/composer.yml

@@ -1,4 +1,13 @@
 ---
 
+- stat: path=/usr/local/bin/composer
+  register: composer_bin
+
+- name: Update composer (phar)
+  command: 'composer self-update'
+  when: composer_bin.stat.exists is defined and composer_bin.stat.exists
+
 - name: Install composer (phar)
   raw: 'curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin/ --filename=composer'
+  when: composer_bin.stat.exists is defined and not composer_bin.stat.exists
+