Investigate why clang-format mangles sources

[43081j]

Currently we're missing a .clang-format so the format npm script won't be using the Google style config.

That's the first issue. Second issue is that if we try use the Google style (copied from polymer tools repo for example), it produces some real strangeness:

@property() message='Hi';

Notice the lack of spacing around =.

return queryFn(this.renderRoot !, selector);

Again crazy spacing around !.

Can we just not use clang-format against template strings and decorators? and typescript-specific stuff?

[sorvell]

A .clang-format was added in #536.

[43081j]

edit: nevermind, the problem was i had clang-format 5 rather than 6 which works fine!