Code review comment for lp:~diogo-simoes89/zorba/data-cleaning

Some minor things that should be changed before approving the merge:

* The documentation for functions like conversion:address-from-phone, conversion:user-from-phone and conversion:address-from-user should be revised, in order to keep just one example (i.e., the one from @example).

* The documentation for functions like normalization:to-date or normalization:to-time should present an example invocation.

* The documentation for the private functions like normalization:check-time should also provide an example invocation. From looking at the source code, it seems to me that these functions are not really necessary, and the corresponding instructions could instead be used directly in the code that
invokes these functions.