fixed courses

src/components/Courses.vue

src/components/CreateEditComponents/CreateCourse.vue

src/components/CreateEditComponents/CreateTeacher.vue

src/components/CreateEditComponents/EditTeacher.vue

src/components/Teachers.vue

src/models/course.js

src/models/teacher.js

src/services/course.service.js

src/services/teacher.service.js

src/store/index.js

src/store/teacher.module.js