Scanner Exercise 3

Write a program that plays a "mad lib".

Ask the user for an animal, and save it to a variable.
Ask the user for a colour, and save it to a variable.
Ask the user for an item of the colour that was entered, and 
save it to a variable.
Ask the user for an action word or phrase, and save it to a 
variable.

Use the inputs to replace items in the poem "Mary Had a Little Lamb":
Mary had a little lamb,
it's fleece as white as snow,
and everywhere that Mary went,
the lamb was sure to go.

- "lamb" is replaced by the animal input
- "white" is replaced by the colour input
- "snow" is replaced by the item of the inputted colour
- "go" is replaced by the action word/phrase input

Sample program run:
Enter an animal: cat
Enter a colour: purple
Enter something purple: grapes
Enter an action word/phrase: code Java

Mary had a little cat,
it's fleece as purple as grapes,
and everywhere that Mary went,
the cat was sure to code Java.

NOTE: if you don't like Mary Had A Little Lamb, use 
something else, but you must ask for at least 4 strings.