Pipe chaining

A really powerful feature of pipes is that they can be chained, where the output from one pipe can serve as the input to another pipe. Consider this example:

{{fullName | slice:0:20 | uppercase}} 

The first pipe slices the first 20 characters of fullName and the second pipe transforms them to uppercase.

Now that we have seen what pipes are and how to use them, why not implement one for the 7 Minute Workout app: a seconds to time pipe?