Use smaller image or svg for logo

[duanwilliam]

we are currently serving a ~240kb, 1280x1280 png image for our logo in the top left (https://github.com/acmucsd/membership-portal-ui/blob/master/src/assets/graphics/logo.png)

this image is displayed at a size of 48x48px

membership-portal-ui/src/layout/components/Header/style.less

Lines 22 to 26 in 3617f49

	.logo {
	height: 3rem;
	margin-right: 1rem;
	width: 3rem;
	}

We can save a fair amount of kb of data by serving an svg instead, or a scaled down image.