Update job ads

Removed Account Manager and Junior Sales Exec, added Support Analyst
Update links
Adding #demo location to /basic
Merge pull request #285 from gocardless/change-job-ads

Change job ads
add your business tracking
Improve text contrast
Remove people
Merge pull request #287 from gocardless/remove-peeps

Remove people
adding logos to index page
adding logos to pro page
Merge pull request #288 from gocardless/add-customer-logos

Add guardian + other logos
Removing creative-industries & zest-digital story & adding redirects
updated head of finance job ad
Update index.html

Removes claim to be the only product that allows you to collect from SEPA, since basic customers can now do this too!
add tracking to whole topbar
add footer tracking
Added a link to the Pro API on the Pro splash page
Merge pull request #291 from gocardless/Pro-API-Link

Added a link to the Pro API on the Pro splash page
adding cta tracking to basic and home
tidied up querystrings