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

static/assets/bootstrap/sass/_alert.sass

@@ -0,0 +1,43 @@
+//
+// Base styles
+//
+
+.alert
+  position: relative
+  padding: $alert-padding-y $alert-padding-x
+  margin-bottom: $alert-margin-bottom
+  border: $alert-border-width solid transparent
+
+  +border-radius($alert-border-radius)
+
+// Headings for larger alerts
+.alert-heading
+  // Specified to prevent conflicts of changing $headings-color
+  color: inherit
+
+// Provide class for links that match alerts
+.alert-link
+  font-weight: $alert-link-font-weight
+
+// Dismissible alerts
+//
+// Expand the right padding and account for the close button's positioning.
+
+.alert-dismissible
+  padding-right: $close-font-size + $alert-padding-x * 2
+
+  // Adjust close link position
+  .close
+    position: absolute
+    top: 0
+    right: 0
+    padding: $alert-padding-y $alert-padding-x
+    color: inherit
+
+// Alternate styles
+//
+// Generate contextual modifier classes for colorizing the alert.
+
+@each $color, $value in $theme-colors
+  .alert-#{$color}
+    +alert-variant(theme-color-level($color, $alert-bg-level), theme-color-level($color, $alert-border-level), theme-color-level($color, $alert-color-level))