fix(@ngtools/webpack): allow Angular 5.0.0

Author: filipesilva

packages/@ngtools/webpack/src/index.ts

@@ -17,8 +17,9 @@ if (compilerCliPath.startsWith(path.dirname(__dirname))) {
                 + 'Please clean your node_modules and reinstall.');
 }
 
-// Throw if we're neither 2.3.1 or more, nor 4.x.y.
-if (!(   version.major == '4'
+// Throw if we're neither 2.3.1 or more, nor 4.x.y, nor 5.x.y.
+if (!(   version.major == '5'
+      || version.major == '4'
       || (version.major == '2'
           && (   version.minor == '4'
               || version.minor == '3' && version.patch == '1')))) {