add subscript as alias of content.

Author: nori0620

SwiftFilePath/PathExtensionDir.swift

@@ -38,6 +38,10 @@ extension Path {
 
 // Add Dir Behavior to Path by extension
 extension Path: SequenceType {
+    
+    public subscript(filename: String) -> Path{
+        get { return self.content(filename) }
+    }
 
     public var children:Array<Path>? {
         assert(self.isDir,"To get children, path must be dir< \(path_string) >")

SwiftFilePathTests/SwiftFilePathTests.swift

@@ -72,7 +72,9 @@ class SwiftFilePathTests: XCTestCase {
 
     func testDir(){
         let dir = sandboxDir.content("bar")
+        let dir2 = sandboxDir["bar"]
         XCTAssertEqual( dir.basename, "bar")
+        XCTAssertEqual( dir.toString(), dir2.toString() )
     }
 
     func testFile() {