Test against a hopefully correct source map output

Introduce libsass version checking in cli.js
and skip the test if running with libsass 3.2.5
or older.

test/cli.js

@@ -7,9 +7,22 @@ var assert = require('assert'),
     stream = require('stream'),
     spawn = require('cross-spawn'),
     cli = path.join(__dirname, '..', 'bin', 'node-sass'),
-    fixture = path.join.bind(null, __dirname, 'fixtures');
+    fixture = path.join.bind(null, __dirname, 'fixtures'),
+    LIBSASS_VERSION = null;
 
 describe('cli', function() {
+  
+  before(function(done) {
+      var bin = spawn(cli, ['-v']);
+      bin.stdout.setEncoding('utf8');
+      bin.stdout.once('data', function(data) {
+        LIBSASS_VERSION = data.trim().split(['\n'])
+          .filter(function(a) { return a.substr(0,7) === 'libsass'; })[0]
+          .split('\t')[1];
+        done();
+      });
+  });
+
   describe('node-sass < in.scss', function() {
     it('should read data from stdin', function(done) {
       var src = fs.createReadStream(fixture('simple/index.scss'));
@@ -399,6 +412,10 @@ describe('cli', function() {
     });
 
     it('should compile with the --source-map option', function(done) {
+      if (LIBSASS_VERSION < '3.3') {
+        this.skip('Source map functionality broken in libsass < 3.3');
+      }
+
       var src = fixture('source-map/index.scss');
       var destCss = fixture('source-map/index.css');
       var destMap = fixture('source-map/index.map');

test/fixtures/source-map/expected.map

@@ -4,7 +4,6 @@
 	"sources": [
 		"index.scss"
 	],
-	"sourcesContent": [],
-	"mappings": "AAAA,OAAO,CAAC;EACN,KAAK,EAAE,GAAI;EACX,MAAM,EAAE,IAAK,GAFN;;AAKD,OAAO,CAAC,EAAE,CAAP;EACT,eAAe,EAAE,IAAK,GADZ;;AAIJ,OAAO,CAAC,EAAE,CAAP;EACT,KAAK,EAAE,IAAK,GADF;EAGV,OAAO,CAAC,EAAE,CAAC,CAAC,CAAV;IACA,WAAW,EAAE,IAAK,GADjB",
+	"mappings": "AAAA,OAAO,CAAC;EACN,KAAK,EAAE,GAAI;EACX,MAAM,EAAE,IAAK,GACd;;AAED,OAAO,CAAC,EAAE,CAAC;EACT,eAAe,EAAE,IAAK,GACvB;;AAED,OAAO,CAAC,EAAE,CAAC;EACT,KAAK,EAAE,IAAK,GAKb;EAND,OAAO,CAAC,EAAE,CAGR,CAAC,CAAC;IACA,WAAW,EAAE,IAAK,GACnB",
 	"names": []
 }