Add responsiveness for footer. Update gulpjs, package.json and bootstrap sass

static/assets/bootstrap/sass/utilities/_text.sass

@@ -0,0 +1,84 @@
+// stylelint-disable declaration-no-important
+
+//
+// Text
+//
+
+.text-monospace
+  font-family: $font-family-monospace
+
+// Alignment
+
+.text-justify
+  text-align: justify !important
+
+.text-nowrap
+  white-space: nowrap !important
+
+.text-truncate
+  +text-truncate
+
+// Responsive alignment
+
+@each $breakpoint in map-keys($grid-breakpoints)
+  +media-breakpoint-up($breakpoint)
+    $infix: breakpoint-infix($breakpoint, $grid-breakpoints)
+
+    .text#{$infix}-left
+      text-align: left !important
+
+    .text#{$infix}-right
+      text-align: right !important
+
+    .text#{$infix}-center
+      text-align: center !important
+
+// Transformation
+
+.text-lowercase
+  text-transform: lowercase !important
+
+.text-uppercase
+  text-transform: uppercase !important
+
+.text-capitalize
+  text-transform: capitalize !important
+
+// Weight and italics
+
+.font-weight-light
+  font-weight: $font-weight-light !important
+
+.font-weight-normal
+  font-weight: $font-weight-normal !important
+
+.font-weight-bold
+  font-weight: $font-weight-bold !important
+
+.font-italic
+  font-style: italic !important
+
+// Contextual colors
+
+.text-white
+  color: $white !important
+
+@each $color, $value in $theme-colors
+  +text-emphasis-variant(".text-#{$color}", $value)
+
+.text-body
+  color: $body-color !important
+
+.text-muted
+  color: $text-muted !important
+
+.text-black-50
+  color: rgba($black, 0.5) !important
+
+.text-white-50
+  color: rgba($white, 0.5) !important
+
+// Misc
+
+.text-hide
+  +text-hide($ignore-warning: true)