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

static/assets/bootstrap/sass/_buttons.sass

@@ -0,0 +1,123 @@
+// stylelint-disable selector-no-qualifying-type
+
+//
+// Base styles
+//
+
+.btn
+  display: inline-block
+  font-weight: $btn-font-weight
+  text-align: center
+  white-space: nowrap
+  vertical-align: middle
+  user-select: none
+  border: $btn-border-width solid transparent
+
+  +button-size($btn-padding-y, $btn-padding-x, $font-size-base, $btn-line-height, $btn-border-radius)
+  +transition($btn-transition)
+
+  // Share hover and focus styles
+  +hover-focus
+    text-decoration: none
+
+
+  &:focus,
+  &.focus
+    outline: 0
+    box-shadow: $btn-focus-box-shadow
+
+  // Disabled comes first so active can properly restyle
+  &.disabled,
+  &:disabled
+    opacity: $btn-disabled-opacity
+
+    +box-shadow(none)
+
+  // Opinionated: add "hand" cursor to non-disabled .btn elements
+  &:not(:disabled):not(.disabled)
+    cursor: pointer
+
+  &:not(:disabled):not(.disabled):active,
+  &:not(:disabled):not(.disabled).active
+    background-image: none
+
+    +box-shadow($btn-active-box-shadow)
+
+    &:focus
+      +box-shadow($btn-focus-box-shadow, $btn-active-box-shadow)
+
+// Future-proof disabling of clicks on `<a>` elements
+a.btn.disabled,
+fieldset:disabled a.btn
+  pointer-events: none
+
+//
+// Alternate buttons
+//
+
+@each $color, $value in $theme-colors
+  .btn-#{$color}
+    +button-variant($value, $value)
+
+@each $color, $value in $theme-colors
+  .btn-outline-#{$color}
+    +button-outline-variant($value)
+
+//
+// Link buttons
+//
+
+// Make a button look and behave like a link
+.btn-link
+  font-weight: $font-weight-normal
+  color: $link-color
+  background-color: transparent
+
+  +hover
+    color: $link-hover-color
+    text-decoration: $link-hover-decoration
+    background-color: transparent
+    border-color: transparent
+
+
+  &:focus,
+  &.focus
+    text-decoration: $link-hover-decoration
+    border-color: transparent
+    box-shadow: none
+
+  &:disabled,
+  &.disabled
+    color: $btn-link-disabled-color
+    pointer-events: none
+
+  // No need for an active state here
+
+//
+// Button Sizes
+//
+
+.btn-lg
+  +button-size($btn-padding-y-lg, $btn-padding-x-lg, $font-size-lg, $btn-line-height-lg, $btn-border-radius-lg)
+
+.btn-sm
+  +button-size($btn-padding-y-sm, $btn-padding-x-sm, $font-size-sm, $btn-line-height-sm, $btn-border-radius-sm)
+
+//
+// Block button
+//
+
+.btn-block
+  display: block
+  width: 100%
+
+  // Vertically space out multiple block buttons
+  + .btn-block
+    margin-top: $btn-block-spacing-y
+
+// Specificity overrides
+input[type="submit"],
+input[type="reset"],
+input[type="button"]
+  &.btn-block
+    width: 100%