Merge homework branch

package-lock.json

package.json

public/index.html

src/actions/homework.js

src/actions/types.js

src/components/App.js

src/components/Footer.js

src/components/Header.css

src/components/forms/AddSolutionForm.js

src/components/forms/CorrectSolutionForm.js

src/components/forms/SolutionDetailsForm.js

src/components/pages/Home.js

src/components/pages/Homework.js

src/components/pages/Profile.js

src/reducers/CorrectSolutionReducer.js

src/reducers/HomeworksReducer.js

src/reducers/index.js