increase version for segwit Reviewers: mark, robert, benchan Reviewed By: benchan Subscribers: ben Differential Revision: https://phabricator.bitgo.com/D6277

update docs, get environment from shell Summary: update docs on starting bitgoexpress get bitgo environment from shell variable BITGO_ENV put an example browser.html to show how to include sdk into browser side app Reviewers: ryan Reviewed By: ryan Subscribers: ben Differential Revision: https://phabricator.bitgo.com/D886