added one more exercise

README.md

@@ -35,3 +35,6 @@
 > * `merging` - Write a function which receives an array of objects. It should merge them into a single object. The objects with fewest values should take precedence over objects with fewer values. The input objects should remain unaffected, by the merge. For example input `[{a: 5}, {a: 3, b: 21, c:32}]` to `{a:5, b:21, c:32}`
 > * `possibleValues` - Write a function which receives an array of objects. Your function should output an object which contains all the keys from input objects. The corresponding value of each key should be an array which contains a list of all values the corresponding key had in all input objects. Values should be unique. For example `[{a: 5}, {a: 3, b: 21, c:32}, {a: 3, c:32}]` to `{a:[5,3], b:[21], c:[32]}`
 > * `isPrime` - Write a function which receives an integer an returns `true` if the input is a prime number, `false` otherwise
+> * `walkabout` - write a constructor called Walker. It should receive one parameter, a string which is either 'N', 'S', 'E' or 'W' which indicates the direction the walker is facing. Walker's initial coordinates should be (0,0), where the first coordinate represents the x coordinate (horizontal) and the second coordinate represents y coordinate (vertical).
+> * Add a `walk` method to `Walker` using its prototype which accepts a direction as a string and a number representing the number of steps to be taken. When called the walker should update its coordinates and add the move made to its journey history. The journey history should be stored using coordinates representing the location at the end of each move.
+> * Add a `pathTaken` method to `Walker` using its prototype. It should output the journey taken taken as a list of coordinates