Use major versions for build dependencies

package.json

@@ -28,21 +28,21 @@
     "react-dom": "^15.6.1"
   },
   "devDependencies": {
-    "autoprefixer": "7.1.3",
-    "babel-cli": "6.26.0",
+    "autoprefixer": "^7.1.3",
+    "babel-cli": "^6.26.0",
     "babel-core": "^6.23.1",
     "babel-eslint": "^7.2.3",
     "babel-loader": "^7.1.0",
-    "babel-plugin-react-intl": "2.3.1",
-    "babel-plugin-syntax-dynamic-import": "6.18.0",
+    "babel-plugin-react-intl": "^2.3.1",
+    "babel-plugin-syntax-dynamic-import": "^6.18.0",
     "babel-plugin-transform-async-to-generator": "^6.24.1",
     "babel-plugin-transform-object-rest-spread": "^6.22.0",
     "babel-preset-es2015": "^6.22.0",
     "babel-preset-react": "^6.22.0",
     "chromedriver": "^2.31.0",
     "classnames": "2.2.5",
-    "copy-webpack-plugin": "4.0.1",
-    "css-loader": "0.28.7",
+    "copy-webpack-plugin": "^4.0.1",
+    "css-loader": "^0.28.7",
     "enzyme": "^2.8.2",
     "eslint": "^4.4.1",
     "eslint-config-scratch": "^4.0.0",
@@ -50,7 +50,7 @@
     "eslint-plugin-react": "^7.2.1",
     "get-float-time-domain-data": "0.1.0",
     "gh-pages": "github:rschamp/gh-pages#publish-branch-to-subfolder",
-    "html-webpack-plugin": "2.30.0",
+    "html-webpack-plugin": "^2.30.0",
     "immutable": "3.8.1",
     "jest": "^20.0.4",
     "lodash.bindall": "4.4.0",
@@ -90,7 +90,7 @@
     "startaudiocontext": "1.2.1",
     "style-loader": "^0.18.0",
     "svg-to-image": "1.1.3",
-    "svg-url-loader": "2.1.0",
+    "svg-url-loader": "^2.1.0",
     "wav-encoder": "1.3.0",
     "web-audio-test-api": "^0.5.2",
     "webpack": "^3.5.4",