Simplify test code
More consistent formatting

(If only I could point gofmt at everything.)
Clean up testing code

Ugh on the error comparison.
Purge goconvey and mock

These packages really impact on test readability with crazy action at a
distance. In addition to this removal of goconvey reduced the test run
time for leveldb on average by about 40-50%.
Drop testing dependencies
Fix build

goleveldb is broken against go1.2 since de350e, so we cannot support
go1.2. This will change when the goleveldb is changed to again support
go1.2.
Merge pull request #52 from kortschak/testing

Simplify testing code