[new feature] normalize size of all icons (#292)

* [bugfix] CouponList always show empty info

* [bugfix] add click feedback of buttons in components

* [Doc] add custom theme document

* [new feature] Notice bar support more props

* [bugfix] PullRefresh test cases

* [bugfix] unused NoticeBar style

* [bugfix] Swipe width calc error

* [Doc] english document of all action components

* [Doc] change document site path to /zanui/vant

* [Doc] fix

* [bugfix] uploader style error

* [bugfix] tabs document demo

* [new feature] Cell support vue-router target route

* [bugfix] add cell test cases

* update yarn.lock

* [bugfix] Tabbar cann't display info when use icon slot

* [Doc] update document title

* [bugfix] Dialog should reset button text when showed

* [new feature] CouponList add showCloseButton prop

* [new feature] Swipe add 'initialSwipe' prop

* [bugfix] NoticeBar text disappeared when page back

* [new feature] ImagePreview support startPosition

* fix: improve imagePreview test cases

* [bugfix] Steps style error when has more than 4 items

* [new feature] normalize size of all icons

packages/vant-css/scripts/icon-template.css

@@ -0,0 +1,22 @@
+@font-face {
+  font-style: normal;
+  font-weight: normal;
+  font-family: '<%= fontName %>';
+  src: url('https://b.yzcdn.cn/zanui/icon/<%= fontName %>.ttf') format('truetype');
+}
+
+.van-icon {
+  display: inline-block;
+  font: normal normal normal 14px/1 "vant-icon";
+  font-size: inherit;
+  text-rendering: auto;
+
+  &:before {
+    display: inline-block;
+  }
+}
+
+<% _.each(glyphs, function(glyph) { %>.van-<%= cssClass %>-<%= glyph.fileName %>:before {
+  content: "\<%= glyph.codePoint %>";
+}
+<% }); %>