Fixed DropShadowFilter.

package.json

@@ -28,9 +28,9 @@
     "license": "LGPL-3.0-or-later",
     "devDependencies": {
         "@pixi/jsdoc-template": "^2.4.3",
-        "eslint": "^6.3.0",
+        "eslint": "^6.4.0",
         "eslint-config-prettier": "^6.3.0",
-        "eslint-plugin-prettier": "^3.1.0",
+        "eslint-plugin-prettier": "^3.1.1",
         "fs-extra": "^8.0.1",
         "gulp": "^4.0.2",
         "gulp-concat": "^2.6.1",
@@ -40,20 +40,20 @@
         "gulp-uglify": "^3.0.2",
         "htmlhint": "^0.11.0",
         "prettier": "^1.18.2",
-        "puppeteer": "^1.19.0",
-        "stylelint": "^10.1.0",
-        "stylelint-config-standard": "^18.3.0"
+        "puppeteer": "^1.20.0",
+        "stylelint": "^11.0.0",
+        "stylelint-config-standard": "^19.0.0"
     },
     "dependencies": {
         "gsap": "^2.1.3",
         "hammerjs": "^2.0.8",
         "optimal-select": "^4.0.1",
-        "pixi-compressed-textures": "^2.0.0",
+        "pixi-compressed-textures": "^2.0.1",
         "pixi-ease": "^2.4.0",
         "pixi-filters": "^3.0.3",
         "pixi-particles": "^4.1.1",
         "pixi-projection": "^0.3.5",
-        "pixi-viewport": "^4.2.2",
+        "pixi-viewport": "^4.2.3",
         "pixi.js": "^5.1.3",
         "propagating-hammerjs": "^1.4.7"
     }