Delete redundant scss files

remove unused scss variables
for reducing package size

src/App.vue

@@ -3,10 +3,10 @@
     <vue-easy-tree
       ref="veTree"
       node-key="id"
-      height="calc(100vh - 20px)"
       :data="treeData"
       :props="props"
       :item-size="26"
+      height="calc(100vh - 30px)"
       show-checkbox
     >
     </vue-easy-tree>

src/assets/common/transition.scss

@@ -1,99 +1,5 @@
 @import "var";
 
-.fade-in-linear-enter-active,
-.fade-in-linear-leave-active {
-  transition: $--fade-linear-transition;
-}
-.fade-in-linear-enter,
-.fade-in-linear-leave,
-.fade-in-linear-leave-active {
-  opacity: 0;
-}
-
-.el-fade-in-linear-enter-active,
-.el-fade-in-linear-leave-active {
-  transition: $--fade-linear-transition;
-}
-.el-fade-in-linear-enter,
-.el-fade-in-linear-leave,
-.el-fade-in-linear-leave-active {
-  opacity: 0;
-}
-
-.el-fade-in-enter-active,
-.el-fade-in-leave-active {
-  transition: all .3s cubic-bezier(.55,0,.1,1);
-}
-.el-fade-in-enter,
-.el-fade-in-leave-active {
-  opacity: 0;
-}
-
-.el-zoom-in-center-enter-active,
-.el-zoom-in-center-leave-active {
-  transition: all .3s cubic-bezier(.55,0,.1,1);
-}
-.el-zoom-in-center-enter,
-.el-zoom-in-center-leave-active {
-  opacity: 0;
-  transform: scaleX(0);
-}
-
-.el-zoom-in-top-enter-active,
-.el-zoom-in-top-leave-active {
-  opacity: 1;
-  transform: scaleY(1);
-  transition: $--md-fade-transition;
-  transform-origin: center top;
-}
-.el-zoom-in-top-enter,
-.el-zoom-in-top-leave-active {
-  opacity: 0;
-  transform: scaleY(0);
-}
-
-.el-zoom-in-bottom-enter-active,
-.el-zoom-in-bottom-leave-active {
-  opacity: 1;
-  transform: scaleY(1);
-  transition: $--md-fade-transition;
-  transform-origin: center bottom;
-}
-.el-zoom-in-bottom-enter,
-.el-zoom-in-bottom-leave-active {
-  opacity: 0;
-  transform: scaleY(0);
-}
-
-.el-zoom-in-left-enter-active,
-.el-zoom-in-left-leave-active {
-  opacity: 1;
-  transform: scale(1, 1);
-  transition: $--md-fade-transition;
-  transform-origin: top left;
-}
-.el-zoom-in-left-enter,
-.el-zoom-in-left-leave-active {
-  opacity: 0;
-  transform: scale(.45, .45);
-}
-
 .collapse-transition {
   transition: 0.3s height ease-in-out, 0.3s padding-top ease-in-out, 0.3s padding-bottom ease-in-out;
 }
-.horizontal-collapse-transition {
-  transition: 0.3s width ease-in-out, 0.3s padding-left ease-in-out, 0.3s padding-right ease-in-out;
-}
-
-.el-list-enter-active,
-.el-list-leave-active {
-  transition: all 1s;
-}
-.el-list-enter, .el-list-leave-active {
-  opacity: 0;
-  transform: translateY(-30px);
-}
-
-.el-opacity-transition {
-  transition: opacity .3s cubic-bezier(.55,0,.1,1);
-}