- Removed "strong" attribute from @property declarations since all properties
  are strong by default.
- Replaced return type "id" with "instancetype" in initializers.
Indented code.
Did more indentation.
Merge branch 'master' of https://github.com/jkereako/issue-4-full-core-data-application

* 'master' of https://github.com/jkereako/issue-4-full-core-data-application:
  Update README.md
Removed unnecessary inclusions.