Added showOn function to IShepherdTourStepOptions

Also bumped documented version to 1.2.0

tether-shepherd/tether-shepherd.d.ts

@@ -1,4 +1,4 @@
-// Type definitions for Tether-Shepherd v1.1.2
+// Type definitions for Tether-Shepherd v1.2.0
 // Project: http://github.hubspot.com/shepherd/
 // Definitions by: Matt Gibbs <https://github.com/mtgibbs>
 // Definitions: https://github.com/borisyankov/DefinitelyTyped
@@ -149,6 +149,7 @@ declare module TetherShepherd {
         showCancelLink?: boolean;
         scrollTo?: boolean;
         when?: any;
+        showOn?: () => boolean;
 
         // TODO: Tie this in with the tether.d.ts
         tetherOptions?: any;