fix: a bug that the height of the column is broken when displayed in IE11 (#1789)

Author: sawa-zen

src/sass/time-column.scss

@@ -5,6 +5,8 @@
   flex-direction: column;
   min-height: 100%;
 
+  height: 100%; // ie-fix
+
   .rbc-timeslot-group {
     flex: 1;
   }