Add e2e tests

vendor/github.com/prometheus/procfs/proc_limits_test.go

@@ -15,14 +15,14 @@ func TestNewLimits(t *testing.T) {
 
 	for _, test := range []struct {
 		name string
-		want int
-		have int
+		want int64
+		have int64
 	}{
 		{name: "cpu time", want: -1, have: l.CPUTime},
 		{name: "open files", want: 2048, have: l.OpenFiles},
 		{name: "msgqueue size", want: 819200, have: l.MsqqueueSize},
 		{name: "nice priority", want: 0, have: l.NicePriority},
-		{name: "address space", want: -1, have: l.AddressSpace},
+		{name: "address space", want: 8589934592, have: l.AddressSpace},
 	} {
 		if test.want != test.have {
 			t.Errorf("want %s %d, have %d", test.name, test.want, test.have)