fix: upgrade a bunch of core dependencies (#77)

package.json

@@ -10,22 +10,22 @@
   ],
   "dependencies": {
     "find-up": "^1.1.2",
-    "istanbul-lib-instrument": "^1.1.4",
+    "istanbul-lib-instrument": "^1.3.1",
     "object-assign": "^4.1.0",
-    "test-exclude": "^3.2.2"
+    "test-exclude": "^3.3.0"
   },
   "devDependencies": {
-    "babel-cli": "^6.3.17",
-    "babel-core": "^6.3.21",
-    "babel-preset-es2015": "^6.3.13",
+    "babel-cli": "^6.18.0",
+    "babel-core": "^6.21.0",
+    "babel-preset-es2015": "^6.18.0",
     "chai": "^3.5.0",
-    "coveralls": "^2.11.9",
+    "coveralls": "^2.11.15",
     "cross-env": "^2.0.1",
-    "mocha": "^3.0.2",
-    "mock-fs": "^3.11.0",
+    "mocha": "^3.2.0",
+    "mock-fs": "^3.12.1",
     "nyc": "^10.0.0",
     "pmock": "^0.2.3",
-    "standard": "^8.0.0",
+    "standard": "^8.6.0",
     "standard-version": "^4.0.0"
   },
   "scripts": {