feat(components): add Select, SelectItem, SelectItemGroup

Closes #31

src/components/Select/Select.stories.js

@@ -0,0 +1,36 @@
+import { withKnobs, text, boolean } from '@storybook/addon-knobs';
+import Component from './Select.Story.svelte';
+
+export default { title: 'Select', decorators: [withKnobs] };
+
+const labelPositions = {
+  'Left (left)': 'left',
+  'Right (right)': 'right'
+};
+
+export const Default = () => ({
+  Component,
+  props: {
+    select: {
+      light: boolean('Light variant (light in <Select>)', false),
+      inline: boolean('Put control in-line with label (inline in <Select>)', false),
+      disabled: boolean('Disabled (disabled in <Select>)', false),
+      hideLabel: boolean('No label (hideLabel in <Select>)', false),
+      invalid: boolean('Show form validation UI (invalid in <Select>)', false),
+      invalidText: text(
+        'Form validation UI content (invalidText in <Select>)',
+        'A valid value is required'
+      ),
+      labelText: text('Label text (helperText)', 'Select'),
+      helperText: text('Helper text (helperText)', 'Optional helper text.')
+    },
+    group: {
+      disabled: boolean('Disabled (disabled in <SelectItemGroup>)', false)
+    }
+  }
+});
+
+export const Skeleton = () => ({
+  Component,
+  props: { story: 'skeleton', hideLabel: boolean('No label (hideLabel in <Select>)', false) }
+});