Make WordPressAPI/ into a real folder

This is to prepare the move to `Sources/` and `Tests/` in a way that
keeps the existing structure intact, for ease of navigation.

Author: mokagio

WordPressKit.xcodeproj/project.pbxproj

@@ -1560,6 +1560,29 @@
 			path = Plans;
 			sourceTree = "<group>";
 		};
+		3FE2E9352BB10D92002CA2E1 /* WordPressAPI */ = {
+			isa = PBXGroup;
+			children = (
+				3FFCC0552BABC78B0051D229 /* WordPressComRESTAPIInterfacing.h */,
+				4A05E7952B2FCB6400C25E3B /* NonceRetrieval.swift */,
+				4A05E7992B2FDC3200C25E3B /* WordPressOrgRestApi.swift */,
+				93BD27741EE73944002BB00B /* HTTPAuthenticationAlertController.swift */,
+				3FFCC0462BAA6EF40051D229 /* NSDate+WordPressCom.swift */,
+				3FFCC04E2BABA6E60051D229 /* Date+WordPressCom.swift */,
+				3FFCC0482BAB98130051D229 /* DateFormatter+WordPressCom.swift */,
+				93BD27771EE73944002BB00B /* WordPressComOAuthClient.swift */,
+				93BD27781EE73944002BB00B /* WordPressComRestApi.swift */,
+				93BD27791EE73944002BB00B /* WordPressOrgXMLRPCApi.swift */,
+				93BD277A1EE73944002BB00B /* WordPressOrgXMLRPCValidator.swift */,
+				93BD277B1EE73944002BB00B /* WordPressRSDParser.swift */,
+				4A11239D2B1926D1004690CF /* HTTPClient.swift */,
+				4A11239B2B1926B7004690CF /* HTTPRequestBuilder.swift */,
+				4A1123992B19269A004690CF /* WordPressAPIError.swift */,
+				4A57A6822B54A326008D0660 /* WordPressAPIError+NSErrorBrdige.swift */,
+			);
+			path = WordPressAPI;
+			sourceTree = "<group>";
+		};
 		404057C3221B30140060250C /* Time Interval */ = {
 			isa = PBXGroup;
 			children = (
@@ -1965,11 +1988,11 @@
 		9368C77D1EC5EF1B0092CE8E /* WordPressKit */ = {
 			isa = PBXGroup;
 			children = (
+				3FE2E9352BB10D92002CA2E1 /* WordPressAPI */,
 				B5A4821F20AC6B5C009D95F6 /* Private */,
 				9368C79C1EC62EBD0092CE8E /* Models */,
 				9368C79B1EC62EB70092CE8E /* Services */,
 				93BD27871EE829B4002BB00B /* Utility */,
-				93BD27731EE7388E002BB00B /* WordPressAPI */,
 				9368C77E1EC5EF1B0092CE8E /* WordPressKit.h */,
 				9368C77F1EC5EF1B0092CE8E /* Info.plist */,
 			);
@@ -2525,29 +2548,6 @@
 			path = "Mock Data";
 			sourceTree = "<group>";
 		};
-		93BD27731EE7388E002BB00B /* WordPressAPI */ = {
-			isa = PBXGroup;
-			children = (
-				3FFCC0552BABC78B0051D229 /* WordPressComRESTAPIInterfacing.h */,
-				4A05E7952B2FCB6400C25E3B /* NonceRetrieval.swift */,
-				4A05E7992B2FDC3200C25E3B /* WordPressOrgRestApi.swift */,
-				93BD27741EE73944002BB00B /* HTTPAuthenticationAlertController.swift */,
-				3FFCC0462BAA6EF40051D229 /* NSDate+WordPressCom.swift */,
-				3FFCC04E2BABA6E60051D229 /* Date+WordPressCom.swift */,
-				3FFCC0482BAB98130051D229 /* DateFormatter+WordPressCom.swift */,
-				93BD27771EE73944002BB00B /* WordPressComOAuthClient.swift */,
-				93BD27781EE73944002BB00B /* WordPressComRestApi.swift */,
-				93BD27791EE73944002BB00B /* WordPressOrgXMLRPCApi.swift */,
-				93BD277A1EE73944002BB00B /* WordPressOrgXMLRPCValidator.swift */,
-				93BD277B1EE73944002BB00B /* WordPressRSDParser.swift */,
-				4A11239D2B1926D1004690CF /* HTTPClient.swift */,
-				4A11239B2B1926B7004690CF /* HTTPRequestBuilder.swift */,
-				4A1123992B19269A004690CF /* WordPressAPIError.swift */,
-				4A57A6822B54A326008D0660 /* WordPressAPIError+NSErrorBrdige.swift */,
-			);
-			name = WordPressAPI;
-			sourceTree = "<group>";
-		};
 		93BD27871EE829B4002BB00B /* Utility */ = {
 			isa = PBXGroup;
 			children = (