rename username to email

app/views/sessions/new.html.erb

@@ -1,7 +1,7 @@
 <h1>Login</h1>
   <%= form_tag '/login' do %>
-  <%= label_tag :username%>
-  <%= text_field_tag :username %>
+  <%= label_tag :email%>
+  <%= text_field_tag :email %>
   <%= label_tag :password%>
   <%= password_field_tag :password%>
   <%= submit_tag "Login"%>

app/views/sessions/welcome.html.erb

@@ -1,6 +1,6 @@
 <h1>Welcome</h1>
 <% if logged_in? %>
-  <h1>You are Logged In, <%= current_user.username %></h1>
+  <h1>You are Logged In, <%= current_user.email %></h1>
   <%= button_to "Logout", '/logout', method: :get%>
 <%else%>
   <%= button_to "Login", '/login', method: :get%>

app/views/users/new.html.erb

@@ -1,7 +1,7 @@
 <h1>Sign Up</h1>
 <%= form_for @user do |f|%>
-  <%= f.label :username%><br>
-  <%= f.text_field :username%><br>
+  <%= f.label :email%><br>
+  <%= f.text_field :email%><br>
   <%= f.label :password%><br>
   <%= f.password_field :password%><br>
   <%= f.submit %>