librime 1.5.3

chore(release): 1.5.3 🎉

Bug Fixes

• cmake, xcode.mk: find optional dependency icu, while building xcode/release-with-icu target [skip appveyor] (17a80f8)
• single_char_filter: broken in librime 1.5.2 (6948a62)

Features

• appveyor: build variant "rime-with-plugins" for tagged commits [skip travis] (eef8c30)
• travis-ci: build variant "rime-with-plugins" for tagged commits [skip appveyor] (cf11c27)
• travis-ci: deploy artifacts for macOS to GitHub releases [skip appveyor] (3f03784)