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

static/assets/bootstrap/sass/mixins/_forms.sass

@@ -0,0 +1,118 @@
+// Form control focus state
+//
+// Generate a customized focus state and for any input with the specified color,
+// which defaults to the `$input-focus-border-color` variable.
+//
+// We highly encourage you to not customize the default value, but instead use
+// this to tweak colors on an as-needed basis. This aesthetic change is based on
+// WebKit's default styles, but applicable to a wider range of browsers. Its
+// usability and accessibility should be taken into account with any change.
+//
+// Example usage: change the default blue border and shadow to white for better
+// contrast against a dark gray background.
+=form-control-focus
+  &:focus
+    color: $input-focus-color
+    background-color: $input-focus-bg
+    border-color: $input-focus-border-color
+    outline: 0
+
+    // Avoid using mixin so we can pass custom focus shadow properly
+    @if $enable-shadows
+      box-shadow: $input-box-shadow, $input-focus-box-shadow
+    @else
+      box-shadow: $input-focus-box-shadow
+
+=form-validation-state($state, $color)
+  .#{$state}-feedback
+    display: none
+    width: 100%
+    margin-top: $form-feedback-margin-top
+    font-size: $form-feedback-font-size
+    color: $color
+
+  .#{$state}-tooltip
+    position: absolute
+    top: 100%
+    z-index: 5
+    display: none
+    max-width: 100%
+
+    // Contain to parent when possible
+    padding: .5rem
+    margin-top: .1rem
+    font-size: .875rem
+    line-height: 1
+    color: $white
+    background-color: rgba($color, 0.8)
+    border-radius: .2rem
+
+  .form-control,
+  .custom-select
+    .was-validated &:#{$state},
+    &.is-#{$state}
+      border-color: $color
+
+      &:focus
+        border-color: $color
+        box-shadow: 0 0 0 $input-focus-width rgba($color, 0.25)
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip
+        display: block
+
+  .form-control-file
+    .was-validated &:#{$state},
+    &.is-#{$state}
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip
+        display: block
+
+  .form-check-input
+    .was-validated &:#{$state},
+    &.is-#{$state}
+      ~ .form-check-label
+        color: $color
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip
+        display: block
+
+  .custom-control-input
+    .was-validated &:#{$state},
+    &.is-#{$state}
+      ~ .custom-control-label
+        color: $color
+
+        &::before
+          background-color: lighten($color, 25%)
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip
+        display: block
+
+      &:checked
+        ~ .custom-control-label::before
+          +gradient-bg(lighten($color, 10%))
+
+      &:focus
+        ~ .custom-control-label::before
+          box-shadow: 0 0 0 1px $body-bg, 0 0 0 $input-focus-width rgba($color, 0.25)
+
+  // custom file
+  .custom-file-input
+    .was-validated &:#{$state},
+    &.is-#{$state}
+      ~ .custom-file-label
+        border-color: $color
+
+        &::before
+          border-color: inherit
+
+      ~ .#{$state}-feedback,
+      ~ .#{$state}-tooltip
+        display: block
+
+      &:focus
+        ~ .custom-file-label
+          box-shadow: 0 0 0 $input-focus-width rgba($color, 0.25)