test(staticprops): replace expected error messages

build(lib): improve the build process

BREAKING CHANGE: removed the alternative es5 builds

feat(handlers): add observer handler hooks

fix(scheduler): fix render order

fix(node): fix node 6 support

fix(ts-definition): fix definition for autoEffect and clearEffect

fix(ts-definition): add autoEffect and clearEffect

fix(engines): remove node 10+ dependency

Node 6 and up is still supported, Node 10 is only required to run some development pipelines

ci(circle): fix semantic-release

6.1.3