User Story 20, User Can Edit their Password

[BrianZanti]

As a registered user
When I visit my profile page
I see a link to edit my password
When I click on the link to edit my password
I see a form with fields for a new password, and a new password confirmation
When I fill in the same password in both fields
And I submit the form
Then I am returned to my profile page
And I see a flash message telling me that my password is updated

DO THESE STORIES FIRST:

• User Story 18, User Profile Show Page

Checklist:

• base tests are written
• base code is written to pass tests
• edge case ("sad path") tests written (if required)
• edge case code written (if required)
• code is reviewed
• branch is merged
• all tests still pass

child of #222

child of #242

depends on #220