feat(@angular/cli): add fallback for CSS variables #7514

Remove explicit dependency on autoprefixer since postcss-cssnext already includes it. Fix failing test:deps.

Author: garoyeri

package.json

@@ -44,7 +44,6 @@
     "@angular-devkit/build-optimizer": "~0.0.18",
     "@angular-devkit/schematics": "~0.0.21",
     "@schematics/angular": "~0.0.30",
-    "autoprefixer": "^6.5.3",
     "chalk": "^2.0.1",
     "circular-dependency-plugin": "^3.0.0",
     "common-tags": "^1.3.1",
@@ -77,6 +76,7 @@
     "nopt": "^4.0.1",
     "opn": "~5.1.0",
     "portfinder": "~1.0.12",
+    "postcss-cssnext": "^3.0.2",
     "postcss-loader": "^1.3.3",
     "postcss-url": "^5.1.2",
     "raw-loader": "^0.5.1",

packages/@angular/cli/package.json

@@ -32,7 +32,6 @@
     "@ngtools/json-schema": "1.1.0",
     "@ngtools/webpack": "1.8.0-beta.0",
     "@schematics/angular": "~0.0.30",
-    "autoprefixer": "^6.5.3",
     "chalk": "^2.0.1",
     "circular-dependency-plugin": "^3.0.0",
     "common-tags": "^1.3.1",