Merge pull request #26 from rommuloifrn/25-enhance-class-creation

feat/refactor: add toast to class renaming when a class with the sent name already exists & isolated toast making in a module

feat: add toast when creating a class with a already used name

build: add toastify-js

feat: class edit input now closes when new name is submitted

feat: edição de classe funcionando, complexidade temporal de O(N*M)

wip: testing class update with alternative method

feat: add "debug" varible in DiagramService

refactor: removed the necessity for an Observable to update currentDiagram data along components

fix: "undefined" left and right symbols of a Relationship

feat: update class (rename, basically)

wip: updateClass method (i think i could have made this simpler than creating a Capsule class...)

refactor: add "id" field to Class model and update methods to use it

refactor: addAttributeOnClass to createAttibute

refactor: rename DiagramService.AddClass() to createClass()