this changes both NewClient and NewTorClient to take a required
parameter for baseURL. removing hard coded api URLS. both still default
to write.as api URLs.

NewDevClient was removed as the base URL can now be provided

one test was still using the production server for tests, changed to dev

Similar to writeas/writeas-cli#22, this change runs goimports on all
files and changes the recommendation in the Contributing section to do
the same.