Fixed #267 Email verification feature (#268)

* <Implemented basic welcome email upon signup>

* <Added config option to enable>

* <Added verification link routing>

* <Added views for verify/resend and reconfigured routes>

* <Finished Verification System minus Rspec changes>

* <Fixed code style>

* <Modified dome rspec tests>

* <Switched sample env back to default>

* <Added test cases to increase code coverage>

* <Added test_helper>

* <Minor code changes>

* <Added requested changes>

* <Added requested changes>

* <see if this fixes migration>

* <see if this fixes migration>

* <fixed migrations>

* Delete .rake_tasks~

* Update _confirm_button.html.erb

* Update _resend_button.html.erb

* Update verify_email.html.erb

* Update verify_email.text.erb

* <Fixed bugs>

* <Added validation of verification link and fixed some code style>

* <Disabled updating email for omniauth>

app/views/shared/settings/_account.html.erb

@@ -27,7 +27,7 @@
       <div class="col-6">
         <%= f.label t("email"), class: "form-label" %>
         <div class="input-icon">
-          <%= f.text_field :email, class: "form-control #{form_is_invalid?(@user, :email)}", placeholder: t("email") %>
+          <%= f.text_field :email, class: "form-control #{form_is_invalid?(@user, :email)}", placeholder: t("email"), readonly: !current_user.greenlight_account? %>
         </div>
       </div>
     </div>