Refactor the tests for travis

tests/run-tests-within-vm

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# A test runner file.
+# Intended to be run from `./run-tests` script *within* a virtual machine.
+# DO NOT run it locally as it might overwrite your `.tmux.conf` (that's what it
+# does during the tests).
+
+CURRENT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+# running test suite is successful by default
+tests_exit_value=0
+
+set_global_exit_val_to_false() {
+	tests_exit_value=1
+}
+
+test_files() {
+	ls -1 "$CURRENT_DIR" |      # test files are in the current dir
+		grep -i '^test' |       # test file names start with 'test'
+		xargs                   # file names in one line
+}
+
+run_tests() {
+	local test_file
+	for test_file in $(test_files); do
+		echo "Running test: $test_file"
+		$CURRENT_DIR/$test_file
+
+		# handling exit value
+		local exit_value="$?"
+		if [ "$exit_value" != 0 ]; then
+			set_global_exit_val_to_false
+		fi
+	done
+}
+
+main() {
+	run_tests
+	exit "$tests_exit_value"
+}
+main