Replace Ansible with Shell script

* Remove Ansible and all Python packages
* Reduce image size by 456 MB (689 MB => 233 MB uncompressed)
* Fixes some open issues, for example, root password is not required if the database already exists.
* Show install and startup traces (traces and errors were hidden by Ansible)

Author: ngosang

root/entrypoint.sh

@@ -56,7 +56,7 @@ provisioner() {
             fi
             install_wallabag
         else
-            echo "WARN: MySQL database is already confiugred. Remove the environment variable with root password."
+            echo "WARN: MySQL database is already configured. Remove the environment variable with root password."
         fi
     fi
 
@@ -77,7 +77,7 @@ provisioner() {
             fi
             install_wallabag
         else
-            echo "WARN: Postgres database is already confiugred. Remove the environment variable with root password."
+            echo "WARN: Postgres database is already configured. Remove the environment variable with root password."
         fi
     fi