add dynamic svg sizing to components. the svg will always fill its parent component and can be resized dynamically.
use actual SVG element for sizing.

add test for component
add test for utils
verify svgs can compute layout from CSS sizing.
verify element sizes are computed correctly.
change test SVG style to remove border since it messes with element size.
Merge pull request #285 from palantir/dynamic-svg-sizing

add dynamic svg sizing to components.