Calculator exercise where you pass in the operation and two numbers.

Requirements:

• Take the phrase: "I <3 JavaScript" (or any three-word phrase).
• The endpoint /phrase should print this string.
• However, the string is built using four handlers!
• The first handler should add a "phrase" key to the "request" object along with the first word and pass it along.
• The second handler should add the second word to the "phrase" key of the "request" object and pass it along.
• The third handler should add the third word to the "phrase" key of the "request" object and pass it along.
• The fourth handler should issue the complete "request.phrase" response, without adding anything to the "request" object at all.

example: GET /phrase --> "I <3 JavaScript"