Move all component styles into a separate CSS file

[sjason19]

Context: Right now most styles are hardcoded into the react component itself, we want to have those moved out of the components and into a respective CSS file.

Example: In src/components/SignIn.js you can see how there is a hardcoded CSS variable called "test" var test = { margin: 'auto', width: '15%', }

What we want to do is to move this into a separate file under src/components/styles and call it SignIn.cs

A good example of how this is done is in src/components/styles/SignUp.css, you can see how all the styles are contained here.