Bump to 0.4.0
Bump to 0.4.0

stellar/js-stellar-base,johansten/js-stellar-base,manran/js-stellar-base,johansten/js-stellar-base,strllar/js-stellar-base,manran/js-stellar-base,strllar/js-stellar-base,manran/js-stellar-base,johansten/js-stellar-base,strllar/js-stellar-base,stellar/js-stellar-base