I have white space between objects when I export to SVG from Illustrator CC 2015.
I have checked that the lines touches in preview mode and I have exported with 3+ decimals.
This is a common problem with SVGs - the transparent line between exactly fitting shapes or between areas which have different colors due blending or transparency, is antialiasing. You can avoid it by having overlapping shapes or inserting something under the seam. One of the shapes a little moved is ok. Even adding a thin stroke helps.