[release] prepare for 1.8.4

1.8.4-SNAPSHOT -> 1.8.4

[release] prepare for 1.8.3

1.8.3-SNAPSHOT -> 1.8.3

[release] prepare for 1.8.2

1.8.2-SNAPSHOT -> 1.8.2

[release] prepare for 1.8.2-RC1

[release] prepare release 1.8.1

[release] prepare release 1.8.1-RC1

[release] prepare release 1.8.0

[release] prepare release 1.8.0-RC1

[pinpoint-apm#4039] 1.7.3 release

[pinpoint-apm#4039] Change to 1.7.3-RC1