Import data from public bodies report

Add model 'finacial report' to represent historical funding and spending
Add rake task to import from public bodies report
Convert public bodies report to UTF-8
Add relation to organisation for financial report
Update schema to reflect migrations

https://www.pivotaltracker.com/story/show/53697273
Merge pull request #703 from ElliotJH/track-historical-funding-on-organisations

https://www.pivotaltracker.com/story/show/53697273

Model public bodies report data.