Merge branch 'M2' into M2-user

# Conflicts:
#	README.md
#	application/model/src/main/java/org/fuseri/model/dto/course/CourseDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/AnswerCreateDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/AnswersCreateDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseCreateDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/ExerciseDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionCreateDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionDto.java
#	application/model/src/main/java/org/fuseri/model/dto/exercise/QuestionUpdateDto.java
#	application/model/src/main/java/org/fuseri/model/dto/lecture/LectureCreateDto.java
#	application/model/src/main/java/org/fuseri/model/dto/user/UserDto.java
#	application/module-certificate/src/main/java/org/fuseri/modulecertificate/service/CertificateController.java
#	application/module-certificate/src/test/java/org/fuseri/modulecertificate/CertificateControllerTests.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/Answer.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerController.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerFacade.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerRepository.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/answer/AnswerService.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainObject.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/common/DomainService.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/Exercise.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseController.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseRepository.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/exercise/ExerciseService.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/Question.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionController.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionFacade.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionRepository.java
#	application/module-exercise/src/main/java/org/fuseri/moduleexercise/question/QuestionService.java
#	application/module-exercise/src/main/resources/application.properties
#	application/module-exercise/src/test/java/org/fuseri/moduleexercise/answer/AnswerTest.java
#	application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseTest.java
#	application/module-exercise/src/test/java/org/fuseri/moduleexercise/question/QuestionTest.java
#	application/module-language-school/pom.xml
#	application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/common/DomainObject.java
#	application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/course/Course.java
#	application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/course/CourseController.java
#	application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/lecture/Lecture.java
#	application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/lecture/LectureController.java
#	application/module-language-school/src/main/java/org/fuseri/modulelanguageschool/user/UserController.java
#	application/module-language-school/src/main/resources/application.properties
#	application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/course/CourseTest.java
#	application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/lecture/LectureTest.java
#	application/module-language-school/src/test/java/org/fuseri/modulelanguageschool/user/UserControllerTest.java