Add cropper library

app/assets/stylesheets/application.scss

@@ -9,6 +9,7 @@
  *= require_self
  *= require dropzone/basic
  *= require cal-heatmap
+ *= require cropper.css
 */
 
 /*

app/assets/stylesheets/cropper.css

+/*!
+ * Cropper v2.3.0
+ * https://github.com/fengyuanchen/cropper
+ *
+ * Copyright (c) 2014-2016 Fengyuan Chen and contributors
+ * Released under the MIT license
+ *
+ * Date: 2016-02-22T02:13:13.332Z
+ */
+.cropper-container {
+  font-size: 0;
+  line-height: 0;
+
+  position: relative;
+
+  -webkit-user-select: none;
+     -moz-user-select: none;
+      -ms-user-select: none;
+          user-select: none;
+
+  direction: ltr !important;
+  -ms-touch-action: none;
+      touch-action: none;
+  -webkit-tap-highlight-color: transparent;
+  -webkit-touch-callout: none;
+}
+
+.cropper-container img {
+  display: block;
+
+  width: 100%;
+  min-width: 0 !important;
+  max-width: none !important;
+  height: 100%;
+  min-height: 0 !important;
+  max-height: none !important;
+
+  image-orientation: 0deg !important;
+}
+
+.cropper-wrap-box,
+.cropper-canvas,
+.cropper-drag-box,
+.cropper-crop-box,
+.cropper-modal {
+  position: absolute;
+  top: 0;
+  right: 0;
+  bottom: 0;
+  left: 0;
+}
+
+.cropper-wrap-box {
+  overflow: hidden;
+}
+
+.cropper-drag-box {
+  opacity: 0;
+  background-color: #fff;
+
+  filter: alpha(opacity=0);
+}
+
+.cropper-modal {
+  opacity: .5;
+  background-color: #000;
+
+  filter: alpha(opacity=50);
+}
+
+.cropper-view-box {
+  display: block;
+  overflow: hidden;
+
+  width: 100%;
+  height: 100%;
+
+  outline: 1px solid #39f;
+  outline-color: rgba(51, 153, 255, .75);
+}
+
+.cropper-dashed {
+  position: absolute;
+
+  display: block;
+
+  opacity: .5;
+  border: 0 dashed #eee;
+
+  filter: alpha(opacity=50);
+}
+
+.cropper-dashed.dashed-h {
+  top: 33.33333%;
+  left: 0;
+
+  width: 100%;
+  height: 33.33333%;
+
+  border-top-width: 1px;
+  border-bottom-width: 1px;
+}
+
+.cropper-dashed.dashed-v {
+  top: 0;
+  left: 33.33333%;
+
+  width: 33.33333%;
+  height: 100%;
+
+  border-right-width: 1px;
+  border-left-width: 1px;
+}
+
+.cropper-center {
+  position: absolute;
+  top: 50%;
+  left: 50%;
+
+  display: block;
+
+  width: 0;
+  height: 0;
+
+  opacity: .75;
+
+  filter: alpha(opacity=75);
+}
+
+.cropper-center:before,
+.cropper-center:after {
+  position: absolute;
+
+  display: block;
+
+  content: ' ';
+
+  background-color: #eee;
+}
+
+.cropper-center:before {
+  top: 0;
+  left: -3px;
+
+  width: 7px;
+  height: 1px;
+}
+
+.cropper-center:after {
+  top: -3px;
+  left: 0;
+
+  width: 1px;
+  height: 7px;
+}
+
+.cropper-face,
+.cropper-line,
+.cropper-point {
+  position: absolute;
+
+  display: block;
+
+  width: 100%;
+  height: 100%;
+
+  opacity: .1;
+
+  filter: alpha(opacity=10);
+}
+
+.cropper-face {
+  top: 0;
+  left: 0;
+
+  background-color: #fff;
+}
+
+.cropper-line {
+  background-color: #39f;
+}
+
+.cropper-line.line-e {
+  top: 0;
+  right: -3px;
+
+  width: 5px;
+
+  cursor: e-resize;
+}
+
+.cropper-line.line-n {
+  top: -3px;
+  left: 0;
+
+  height: 5px;
+
+  cursor: n-resize;
+}
+
+.cropper-line.line-w {
+  top: 0;
+  left: -3px;
+
+  width: 5px;
+
+  cursor: w-resize;
+}
+
+.cropper-line.line-s {
+  bottom: -3px;
+  left: 0;
+
+  height: 5px;
+
+  cursor: s-resize;
+}
+
+.cropper-point {
+  width: 5px;
+  height: 5px;
+
+  opacity: .75;
+  background-color: #39f;
+
+  filter: alpha(opacity=75);
+}
+
+.cropper-point.point-e {
+  top: 50%;
+  right: -3px;
+
+  margin-top: -3px;
+
+  cursor: e-resize;
+}
+
+.cropper-point.point-n {
+  top: -3px;
+  left: 50%;
+
+  margin-left: -3px;
+
+  cursor: n-resize;
+}
+
+.cropper-point.point-w {
+  top: 50%;
+  left: -3px;
+
+  margin-top: -3px;
+
+  cursor: w-resize;
+}
+
+.cropper-point.point-s {
+  bottom: -3px;
+  left: 50%;
+
+  margin-left: -3px;
+
+  cursor: s-resize;
+}
+
+.cropper-point.point-ne {
+  top: -3px;
+  right: -3px;
+
+  cursor: ne-resize;
+}
+
+.cropper-point.point-nw {
+  top: -3px;
+  left: -3px;
+
+  cursor: nw-resize;
+}
+
+.cropper-point.point-sw {
+  bottom: -3px;
+  left: -3px;
+
+  cursor: sw-resize;
+}
+
+.cropper-point.point-se {
+  right: -3px;
+  bottom: -3px;
+
+  width: 20px;
+  height: 20px;
+
+  cursor: se-resize;
+
+  opacity: 1;
+
+  filter: alpha(opacity=100);
+}
+
+.cropper-point.point-se:before {
+  position: absolute;
+  right: -50%;
+  bottom: -50%;
+
+  display: block;
+
+  width: 200%;
+  height: 200%;
+
+  content: ' ';
+
+  opacity: 0;
+  background-color: #39f;
+
+  filter: alpha(opacity=0);
+}
+
+@media (min-width: 768px) {
+  .cropper-point.point-se {
+    width: 15px;
+    height: 15px;
+  }
+}
+
+@media (min-width: 992px) {
+  .cropper-point.point-se {
+    width: 10px;
+    height: 10px;
+  }
+}
+
+@media (min-width: 1200px) {
+  .cropper-point.point-se {
+    width: 5px;
+    height: 5px;
+
+    opacity: .75;
+
+    filter: alpha(opacity=75);
+  }
+}
+
+.cropper-invisible {
+  opacity: 0;
+
+  filter: alpha(opacity=0);
+}
+
+.cropper-bg {
+  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAQMAAAAlPW0iAAAAA3NCSVQICAjb4U/gAAAABlBMVEXMzMz////TjRV2AAAACXBIWXMAAArrAAAK6wGCiw1aAAAAHHRFWHRTb2Z0d2FyZQBBZG9iZSBGaXJld29ya3MgQ1M26LyyjAAAABFJREFUCJlj+M/AgBVhF/0PAH6/D/HkDxOGAAAAAElFTkSuQmCC');
+}
+
+.cropper-hide {
+  position: absolute;
+
+  display: block;
+
+  width: 0;
+  height: 0;
+}
+
+.cropper-hidden {
+  display: none !important;
+}
+
+.cropper-move {
+  cursor: move;
+}
+
+.cropper-crop {
+  cursor: crosshair;
+}
+
+.cropper-disabled .cropper-drag-box,
+.cropper-disabled .cropper-face,
+.cropper-disabled .cropper-line,
+.cropper-disabled .cropper-point {
+  cursor: not-allowed;
+}