updating english title and description meta data for mortgage calculator
adding canonical url meta data for mortgage, stamp duty and mortgage affordability calculators
seo changes for stamp-duty-calculator to english title and description
updating minor version number
Merge pull request #218 from moneyadviceservice/seo_updates

Seo updates
Add directive to convert a link tag button to a button tag button.

Accessibility wants consistent use of buttons and links. Because we're
supporting javascript-less situations, we need submit in one place and
link in another. When javascript is on, we can make links buttons to
match the form buttons.
update spec to reflect change in directive
Don't auto focus on the first input for accessibility.