Add different environments for assets

yarn.lock

@@ -384,6 +384,13 @@ core-util-is@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
 
+cross-env:
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/cross-env/-/cross-env-5.0.1.tgz#ff4e72ea43b47da2486b43a7f2043b2609e44913"
+  dependencies:
+    cross-spawn "^5.1.0"
+    is-windows "^1.0.0"
+
 cross-spawn@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-3.0.1.tgz#1256037ecb9f0c5f79e3d6ef135e30770184b982"
@@ -398,7 +405,7 @@ cross-spawn@^4.0.0, cross-spawn@~4.0.0:
     lru-cache "^4.0.1"
     which "^1.2.9"
 
-cross-spawn@^5.0.1:
+cross-spawn@^5.0.1, cross-spawn@^5.1.0:
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-5.1.0.tgz#e8bd0efee58fcff6f8f94510a0a554bbfa235449"
   dependencies:
@@ -1137,6 +1144,10 @@ is-windows@^0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/is-windows/-/is-windows-0.2.0.tgz#de1aa6d63ea29dd248737b69f1ff8b8002d2108c"
 
+is-windows@^1.0.0:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/is-windows/-/is-windows-1.0.1.tgz#310db70f742d259a16a369202b51af84233310d9"
+
 isarray@~1.0.0, isarray@1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
@@ -2261,6 +2272,10 @@ uglify-js@^3.0.6:
     commander "~2.9.0"
     source-map "~0.5.1"
 
+uglifycss:
+  version "0.0.27"
+  resolved "https://registry.yarnpkg.com/uglifycss/-/uglifycss-0.0.27.tgz#53553b8115de26dce57b42ba0b34e88dd80d0cde"
+
 uid-number@^0.0.6:
   version "0.0.6"
   resolved "https://registry.yarnpkg.com/uid-number/-/uid-number-0.0.6.tgz#0ea10e8035e8eb5b8e4449f06da1c730663baa81"