chore(deps): update dependency typescript to v2.8.4 (#264)

Author: renovate[bot]

package.json

@@ -62,7 +62,7 @@
     "semantic-release": "15.5.0",
     "tslint": "5.10.0",
     "tslint-config-prettier": "1.13.0",
-    "typescript": "2.8.3"
+    "typescript": "2.8.4"
   },
   "keywords": [
     "behavior-smooth",

yarn.lock

@@ -5073,7 +5073,11 @@ typescript-compiler@^1.4.1-2:
   version "1.4.1-2"
   resolved "https://registry.yarnpkg.com/typescript-compiler/-/typescript-compiler-1.4.1-2.tgz#ba4f7db22d91534a1929d90009dce161eb72fd3f"
 
-[email protected], typescript@^2.4.2:
+[email protected]:
+  version "2.8.4"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.8.4.tgz#0b1db68e6bdfb0b767fa2ab642136a35b059b199"
+
+typescript@^2.4.2:
   version "2.8.3"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.8.3.tgz#5d817f9b6f31bb871835f4edf0089f21abe6c170"