tests: Make tests operate in /tmp director instead of src.

Thanks to this, unix sockets should be not longer
created by integration tests in the the source code directory,
so potentially trigger IDE reloads and unnecessery load (and mess).

pkg/testutil/leak.go

@@ -97,6 +97,10 @@ func CheckAfterTest(d time.Duration) error {
 // BeforeTest is a convenient way to register before-and-after code to a test.
 // If you execute BeforeTest, you don't need to explicitly register AfterTest.
 func BeforeTest(t testing.TB) {
+	if err := CheckAfterTest(10 * time.Millisecond); err != nil {
+		t.Skipf("Found leaked goroutined BEFORE test", err)
+		return
+	}
 	t.Cleanup(func() {
 		AfterTest(t)
 	})