Increase `fade` transition, to work around timing bug

in bootstrap.native.

https://github.com/thednp/bootstrap.native/issues/192

css/converse.css

@@ -4911,6 +4911,9 @@ body.reset {
     opacity: 0; }
   100% {
     opacity: 1; } }
+  #conversejs .fade {
+    opacity: 0;
+    transition: opacity 0.20s linear; }
   #conversejs .fade-in {
     opacity: 0;
     /* make things invisible upon start */

css/inverse.css

@@ -4911,6 +4911,9 @@ body.reset {
     opacity: 0; }
   100% {
     opacity: 1; } }
+  #conversejs .fade {
+    opacity: 0;
+    transition: opacity 0.20s linear; }
   #conversejs .fade-in {
     opacity: 0;
     /* make things invisible upon start */

sass/_core.scss

@@ -242,6 +242,11 @@ body.reset {
         100% { opacity: 1 }
     }
 
+    .fade {
+        opacity: 0;
+        transition: opacity 0.20s linear;
+    }
+
     .fade-in {
         @include fade-in;
     }