take out borders around swap panel & update theme list

src/app.js

@@ -91,7 +91,7 @@ var css = csjs`
     left               : 0;
     overflow           : hidden;
     width              : 50px;
-    border-right       : 1px solid var(--primary);
+    /* border-right       : 1px solid var(--primary); */
   }
   .swappanel          {
     display            : flex;

src/app/ui/styles-guide/theme-chooser.js

@@ -6,15 +6,18 @@ const themes = [
   {name: 'Cerulean', quality: 'light', url: 'https://bootswatch.com/4/cerulean/bootstrap.min.css'},
   {name: 'Flatly', quality: 'light', url: 'https://bootswatch.com/4/flatly/bootstrap.min.css'},
   {name: 'Lumen', quality: 'light', url: 'https://bootswatch.com/4/lumen/bootstrap.min.css'},
+  {name: 'Minty', quality: 'light', url: 'https://bootswatch.com/4/minty/bootstrap.min.css'},
+  {name: 'Pulse', quality: 'light', url: 'https://bootswatch.com/4/pulse/bootstrap.min.css'},
   {name: 'Sandstone', quality: 'light', url: 'https://bootswatch.com/4/sandstone/bootstrap.min.css'},
   {name: 'Spacelab', quality: 'light', url: 'https://bootswatch.com/4/spacelab/bootstrap.min.css'},
   {name: 'Yeti', quality: 'light', url: 'https://bootswatch.com/4/yeti/bootstrap.min.css'},
   {name: 'Cyborg', quality: 'dark', url: 'https://bootswatch.com/4/cyborg/bootstrap.min.css'},
   {name: 'Darkly', quality: 'dark', url: 'https://stackpath.bootstrapcdn.com/bootswatch/4.3.1/darkly/bootstrap.min.css'},
-  {name: 'Slate', quality: 'dark', url: 'https://stackpath.bootstrapcdn.com/bootswatch/4.3.1/slate/bootstrap.min.css'}
+  {name: 'Slate', quality: 'dark', url: 'https://stackpath.bootstrapcdn.com/bootswatch/4.3.1/slate/bootstrap.min.css'},
+  {name: 'Superhero', quality: 'dark', url: 'https://stackpath.bootstrapcdn.com/bootswatch/4.3.1/superhero/bootstrap.min.css'}
 ]
 
-const defaultTheme = 'Superhero'
+const defaultTheme = 'Cerulean'
 
 module.exports = {
   event: new EventEmitter(),

src/lib/panels-resize.js

@@ -10,7 +10,7 @@ const css = csjs`
     bottom            : 0;
     cursor            : col-resize;
     z-index           : 999;
-    border-right      : 2px solid var(--primary);
+    /* border-right      : 2px solid var(--primary); */
   }
   .ghostbar           {
     width             : 3px;