ignore some direction like None and Not Computable

lib/api/alexa/index.js

@@ -110,8 +110,6 @@ function configure (app, wares, ctx, env) {
                 direction = ' and rapidly dropping';
             } else if (records[0].direction === 'DoubleUp') {
                 direction = ' and rapidly rising';
-            } else {
-                direction = records[0].direction;
             }
             var status = sbx.scaleMgdl(records[0].sgv) + direction + ' as of ' + moment(records[0].date).from(moment(sbx.time));
             callback('Current blood glucose', status);