test(am-time-ago): add test for setting the `datetime` attribute of `time` elements (#41)
test(am-time-ago): add test for `amTimeAgoConfig.serverTime` configuration option (#54)
doc(am-time-ago): improve documentation for `amTimeAgoConfig.serverTime` (#53)
test(am-time-ago): organize one-time binding tests, remove redundant test cases (#54)
chore(*): release 0.8.0