Added Spine plugin webpack build

Author: photonstorm

.eslintignore

@@ -10,6 +10,9 @@ src/utils/object/Extend.js
 src/structs/RTree.js
 src/dom/_ScaleManager.js
 src/dom/VisualBounds.js
+plugins/spine/src/spine-canvas.js
+plugins/spine/src/spine-webgl.js
+webpack.*
 webpack.config.js
 webpack.dist.config.js
 webpack.fb.config.js