typos in streamtube meta

Author: alexcjohnson

src/traces/streamtube/index.js

@@ -41,11 +41,11 @@ module.exports = {
 
     meta: {
         description: [
-            'Use streamtube trace to visualize flow in a vector fields.',
+            'Use a streamtube trace to visualize flow in a vector field.',
             '',
             'Specify a vector field using 6 1D arrays of equal length,',
             '3 position arrays `x`, `y` and `z`',
-            'and 3 vector component arrays `u`, `v`, `w`.',
+            'and 3 vector component arrays `u`, `v`, and `w`.',
             '',
             'By default, the tubes\' starting positions will be cut from the vector field\'s',
             'x-z plane at its minimum y value.',