Form a portfolio from a user selected group of stocks

[TTitcombe]

As a user, I must be able to select multiple stocks, associated with a number of shares. I should be able to see the value of this portfolio.

Acceptance criteria:

• The gui should display current stocks in the portfolio, the number of shares for the stock, and the total value of the portfolio in dollars
• The gui should have a button for adding and removing stocks from a portfolio
• You should be able to add or remove shares from a stock in the portfolio without removing it from the portfolio
• The number of shares should be validated to ensure it is a positive integer which is less than total number of shares available for the company

Points: 5