fix border color on inverse tables

dist/css/bootstrap.css

@@ -1846,7 +1846,7 @@ table td[class*="col-"], table th[class*="col-"] {
 .table-inverse.table-bordered {
   border: 0;
 }
-.table-inverse th, .table-inverse td {
+.table-inverse th, .table-inverse td, .table-inverse thead th {
   border-color: #55595c;
 }
 

docs/dist/css/bootstrap.css

@@ -1846,7 +1846,7 @@ table td[class*="col-"], table th[class*="col-"] {
 .table-inverse.table-bordered {
   border: 0;
 }
-.table-inverse th, .table-inverse td {
+.table-inverse th, .table-inverse td, .table-inverse thead th {
   border-color: #55595c;
 }
 

scss/_tables.scss

@@ -181,7 +181,8 @@ table {
   }
 
   th,
-  td {
+  td,
+  thead th {
     border-color: $gray;
   }
 }