Support bootstrap 4

Hi @AllenFang:

I’m trying to support bootstrap 4 and I’ll take a look on how it was implemented in react-bootstrap-table. It would be take refer to but won’t be the same. If there’s any concern or advices, please let me know. Thanks a lot 😃

[ssorallen]

I’ve been using react-bootstrap-table2 with Bootstrap 4.1.1, and so far the only thing I’ve needed to add is the caret. This is the CSS I added to my project so far:

/* Caret from Bootstrap 3 */
.caret {
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: 2px;
  vertical-align: middle;
  border-top: 4px dashed;
  border-top: 4px solid;
  border-right: 4px solid transparent;
  border-left: 4px solid transparent;
}

.dropup .caret {
  border-bottom: 4px dashed;
  border-top: 0;
  content: '';
}

/* Prevent excessive margin from react-table from increasing the height of the
 * `<thead>`.
 */
.react-bootstrap-table th > .react-bootstrap-table-sort-order > .caret,
.react-bootstrap-table th .order > .dropdown > .caret,
.react-bootstrap-table th .order > .dropup > .caret {
  margin-bottom: 0;
  margin-top: 0;
}

Thanks for all the work on this project. The table works great!

[ssorallen]

Also the table-condensed class changed to table-sm. The condensed prop for ReactBootstrapTable2 adds the incorrect class name right now and has no effect. You can get around it by using classes="table-sm" right now.