Adding a new function `dateToTimeZone` to AbstractBuilder

The function convert a a string into a proper date object, whith the specified timeZone for the builder.
By default, its GMT+2 (Europe/Paris) time.

This is justified by the fact that the timeZone is not saved in the BDD so we need to specify a default one
Fix typo
Merge pull request #37 from Evaneos/datetime-builder

Adding a new function `dateToTimeZone` to AbstractBuilder