chore(sample): add sample travis-install script

sample/README.md

@@ -70,6 +70,14 @@ and build script.
 To build the sample plugin as standard Rime plugin, link or copy the source code
 directory to `plugins/sample` and turn off cmake flag `BUILD_SAMPLE=OFF`.
 
+https://github.com/rime/librime-sample is the same sample plugin in its separate
+GitHub repository. You can checkout plugins (a list of slugs) with this command:
+
+``` shell
+cd librime
+bash install-plugins.sh rime/librime-sample # ...
+```
+
 The cmake option `BUILD_MERGED_PLUGINS` merges all detected plugins into the
 built `rime` library. Set the option off to build each plugin as a standalone
 (shared) library. In the latter case, the user needs to explicitly load the

sample/travis-install.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+if [[ "$TRAVIS_OS_NAME" == linux ]]; then
+    echo "TODO: in this script, install the Rime plugin's dependencies for Linux"
+elif [[ "$TRAVIS_OS_NAME" == osx ]]; then
+    echo "TODO: in this script, install the Rime plugin's dependencies for macOS"
+fi