Add `.text-wrap` class.

this is the opposite of `.text-nowrap`, and a forces elements to wrap onto new lines.

One use case for this is extra long button text. Bootstrap buttons by default do no wrap, so this class could be used to override that behavior.

scss/utilities/_text.scss

@@ -9,6 +9,7 @@
 // Alignment
 
 .text-justify  { text-align: justify !important; }
+.text-wrap     { white-space: normal !important; }
 .text-nowrap   { white-space: nowrap !important; }
 .text-truncate { @include text-truncate; }