Build:Tests: Fix custom build tests, verify on Travis

This commit fixes unit tests for the following builds:

1. The no-deprecated build: `custom:-deprecated`
2. The current slim build: `custom:-ajax,-effects`
3. The future (#4553) slim build: `custom:-ajax,-callbacks,-deferred,-effects`

It also adds separate Travis jobs for the no-deprecated & slim builds. 

Closes gh-4577

1 files changed, 24 insertions, 0 deletions

diff --git a/src/core/parseXML.js b/src/core/parseXML.js
new file mode 100644
index 000000000..d547eab53
--- /dev/null
+++ b/src/core/parseXML.js
@@ -0,0 +1,24 @@
+import jQuery from "../core.js";
+
+// Cross-browser xml parsing
+jQuery.parseXML = function( data ) {
+	var xml;
+	if ( !data || typeof data !== "string" ) {
+		return null;
+	}
+
+	// Support: IE 9 - 11+
+	// IE throws on parseFromString with invalid input.
+	try {
+		xml = ( new window.DOMParser() ).parseFromString( data, "text/xml" );
+	} catch ( e ) {
+		xml = undefined;
+	}
+
+	if ( !xml || xml.getElementsByTagName( "parsererror" ).length ) {
+		jQuery.error( "Invalid XML: " + data );
+	}
+	return xml;
+};
+
+export default jQuery.parseXML;