Bring iframe to front

With the new logging interface there's less space for the test itself.
Put the iframe above and over the rest of the page reserving only the space for the top bar.

Close #44
1.2.0
Refactor attester as a module

Make attester as a module that can be used by other node modules and not only a command line tool.

Responsibilities are split in different submodules that communicate through an event bus that allows a greater extensibility.