Add very simple test cases

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

tests/run_one_test.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+if [ -z $DISPLAY ]; then
+	exec xvfb-run -s "+extension composite" -a $0 $1 $2
+fi
+
+echo "Running test $2"
+
+# TODO keep the log file, and parse it to see if test is successful
+($1 --experimental-backends --backend dummy --log-level=debug --log-file=/dev/null) &
+compton_pid=$!
+$2
+
+kill -INT $compton_pid
+
+