refactor(CLI): rename lib/cli/cli.js to lib/cli/options.js (#1045)

The path `lib/cli/cli.js` is confusing. Rename to `options.js` which is
how we were already referencing the file in `lib/cli/etcher.js`.

Signed-off-by: Juan Cruz Viotti <jviotti@openmailbox.org>

lib/cli/etcher.js

@@ -24,7 +24,7 @@ const form = require('resin-cli-form');
 const drivelist = Bluebird.promisifyAll(require('drivelist'));
 const writer = require('./writer');
 const errors = require('./errors');
-const options = require('./cli');
+const options = require('./options');
 const robot = require('../shared/robot');
 const messages = require('../shared/messages');
 const EXIT_CODES = require('../shared/exit-codes');