README: Reflect changes made for sass#611.

README.md

@@ -314,11 +314,7 @@ Note `--importer` takes the (absolute or relative to pwd) path to a js file, whi
 
 ## Post-install Build
 
-Install runs a series of Mocha tests to see if your machine can use the pre-built [libsass] which will save some time during install. If any tests fail it will build from source.
-
-If you know the pre-built version will work and do not want to wait for the tests to run you can skip the tests by setting the environment variable `SKIP_NODE_SASS_TESTS` to true.
-
-      SKIP_NODE_SASS_TESTS=true npm install
+Install runs only two Mocha tests to see if your machine can use the pre-built [libsass] which will save some time during install. If any tests fail it will build from source.
 
 ## Maintainers