Bump convert-source-map dependency, clean up duplicate require call

* convert-source-map@^1.2.0

The generateMapFileComment() method used in #662 isn't available in v1.1.2.

* use already required convert-source-map dependency

No need to require the generateMapFileComment() method separately.

Also remove unnecessary linebreak at the end of the file.

Author: novemberborn

lib/caching-precompiler.js

@@ -1,7 +1,6 @@
 'use strict';
 var path = require('path');
 var fs = require('fs');
-var generateMapFileComment = require('convert-source-map').generateMapFileComment;
 var convertSourceMap = require('convert-source-map');
 var cachingTransform = require('caching-transform');
 var objectAssign = require('object-assign');
@@ -84,7 +83,7 @@ CachingPrecompiler.prototype._transform = function (code, filePath, hash) {
 	// is cached. This will allow the source map to be resolved.
 	var dirPath = path.dirname(filePath);
 	var relativeMapPath = path.relative(dirPath, mapPath);
-	var comment = generateMapFileComment(relativeMapPath);
+	var comment = convertSourceMap.generateMapFileComment(relativeMapPath);
 
 	return result.code + '\n' + comment;
 };
@@ -182,4 +181,3 @@ CachingPrecompiler.prototype._generateHash = function (code, filePath, salt) {
 
 	return hash;
 };
-

package.json

@@ -94,7 +94,7 @@
     "cli-truncate": "^0.2.0",
     "co-with-promise": "^4.6.0",
     "common-path-prefix": "^1.0.0",
-    "convert-source-map": "^1.1.2",
+    "convert-source-map": "^1.2.0",
     "core-assert": "^0.1.0",
     "debug": "^2.2.0",
     "empower-core": "^0.5.0",