set up controllers/views/routes for uploading

in order to actually upload a file we need a controller and a form for
doing so. Since the routes will get be at GET /import and POST /import
the form doesn't need to take a action, but it does need to be multipart
in order to accept file data. there are no models to associate with this
form so I just use a _tag helpers to create it.

the response is equally as simple with only the bare minimum in
error-checking (it checks to see if the form is there). since the data
is promised to be properly formatted and all there, this is technically
all that is needed for the problem.
add some rudimentary error checking to the import action

while it's true that we expect to inputs to be correct, it still feels
wrong to have IO without any error catching. this adds some minimal
error checking for the kinds of errors we might expect
(ActiveRecord::RecordInvalid and IOError) from our form parsing.
specify gem versions for compatibility

while developing this application I wasn't strict about gem versions,
but now that it's finished I want to ensure that it will work for
whoever uses it in the future.
add instructions for setting up the application

although the application runs on just about all of rails' conventions,
it's important to have all of the dependencies and installation
procedures listed in the README.