add debug info
add user#show action  7.1.2
add tests for user show page
7.1.4 A Gravatar image and a sidebar
7.2.1 Tests for user signup
7.2.2 Using form_for and creating new user view form
7.3.1  add user#create action
7.3.2 Strong Parameters. Create user_params helper for passing params
7.3.3 Add error messages for incorrect signup form entries
7.4.2  Add flash message for new user signup