Implements first pass at csv exports of reports

[desmondmorris]

References #35 (possibly fixes for now?)
This is a rough first pass at CSV exports for reports. The merge includes

• A new route "/reports/export"
• A new method in the AssetController ("exportReports"). This method borrows functionality from the getReports method and spits out the list of assets in csv format ("report.csv")

There may be a good argument to create a separate Reports controller to manage the reporting routes and export functionality. Seems a little dirty to stuff it in the assets controller. This merge does not account for paging.

I should probably add some tests to this thing too.

[snipe]

Definitely need this in a reports controller at some point - we'll also have more reports than just depreciation, so what we have was just to get something out there, check the depreciation math, etc.

I don't think we need pagination in a csv export, do we? I would expect a full dump on csv export.

And hey - thanks so much for working on this - I'm stoked we get to work on something together!

[desmondmorris]

No problem. I am excited too!