Change the format of the request log files to json to simplify
manual edition of those files.
Add variables functionality.

To use it create 'variables.json' file inside of the request log directory.
Example content of this file:

{
    "user_name" : "fh-level7user7",
    "user_password" : "fh-level7user7"
}

Then you can use placeholders in the request filed to tell the app
to substitute some data in the request logs before the execution.
Format of the placeholder is: {{<variable_name>}}. For instance
{{user_name}} will be replaced with fh-level7user7.
Add request parameters with substitutions into the short block.
Rewrite some parts to use ModelLogEntry instead of just array
Implement actions on logs.

You can add configuration to the log file to execute various
actions before and after the log execution. For example:

    "pre_actions": [
        {"action": "AssertUsedVariablesDefined"},
        {"action": "AssertVariableNotEmpty", "variable_name":"user_language"}
    ],
    "post_actions": [
        {"action": "AssertResponseCodeIs200"}
    ]
Extract data methods into the separate class to use it in other places
Pass action configuration from log to the object.
Extend variables handler from DataObject to simplify work with it's data.
Implement ActionAssertVariableDefined action
Implement ActionAssertUsedVariablesDefined.php
Implement ActionAssertResponseCodeIs200
Implement ActionUnsetVariable
Implement ActionExtractVariableRegExp
Inherit DataObject from ArrayAccess to simplify work with it.
Encapsulate namespace in class.
Show error messages in cli