[TravisCI] updated for dox upstream change.

Notice that it would still fail until this is merged: https://github.com/dpeek/dox/pull/77
[ci skip]

tests/RunTravis.hx

@@ -382,7 +382,7 @@ class RunTravis {
 				haxelibInstallGit("HaxeFoundation", "hxcs", true);
 
 				haxelibInstallGit("dpeek", "dox", true);
-				changeDirectory(getHaxelibPath("dox") + "..");
+				changeDirectory(getHaxelibPath("dox"));
 				runCommand("haxe", ["run.hxml"]);
 				runCommand("haxe", ["gen.hxml"]);
 				haxelibRun(["dox", "-o", "bin/api.zip", "-i", "bin/xml"]);