[#1] Implemented handler and defined behaviour.
[#1] Added event record. Added no-cache header. Updated the README.
[#1] Improved implementation. Added and renamed behavior functions. Removed event record.
[Closes #1] Updated README. Removed argument from behavior function.
[#1] Fixed doc string. Added types to record fields. Replaced tuple() type for {}.
[#1] Added validation in case the module is missing when using the proplist format for options.
[#1] Modified the arity of the init callback, passing the request to the implementing module.
[#1] Replaced function for list comprehension. Replaced case for pattern matching.
[#1] Replaced no_state for empty #state{}. Fixed typo in README.
Merge pull request #5 from inaka/jfacorro.1.do.everything

[#1] lasse_handler and related behavior implementation