Update bem-core to 4.3.1

Author: tadatuta

bower.json

@@ -23,7 +23,7 @@
     "!LICENSE.txt"
   ],
   "dependencies": {
-    "bem-core": "4.2.0"
+    "bem-core": "4.3.1"
   },
   "devDependencies": {
     "bem-pr": "~0.13.0"

package.json

@@ -28,7 +28,7 @@
   ],
   "dependencies": {},
   "peerDependency": {
-    "bem-core": "^4.2.0"
+    "bem-core": "^4.3.1"
   },
   "devDependencies": {
     "autoprefixer": "^6.4.0",