Implementing compatibility with go latest

This should allow darwin to be compatible with all the latest

go1.7.x
go1.8.x
go1.9.x

.travis.yml

@@ -9,10 +9,6 @@ go:
   - 1.8.x
   - 1.9.x
   - 1.10.x
-  # from go 1.8.7, 1.9.4, 1.10rc2 there is a restriction on CGO see https://github.com/bugst/go-serial/issues/50
-  # this restriction has some consequences on darwin build
-  - 1.8.6
-  - 1.9.3
 
 go_import_path: go.bug.st/serial.v1
 
@@ -31,14 +27,6 @@ env:
 
 matrix:
   exclude:
-  - os: linux # no point in testing go1.8.6 on Linux
-    go: 1.8.6
-  - os: linux # no point in testing go1.9.3 on Linux
-    go: 1.9.3
-  - os: osx   # go1.8.x after 1.8.6 is not supported on OSX
-    go: 1.8.x
-  - os: osx   # go1.9.x after 1.9.3 is not supported on OSX
-    go: 1.9.x
   - os: linux
     env: TEST_OS=darwin TEST_ARCH=386
   - os: linux

enumerator/usb_darwin_go1.9.go

@@ -10,18 +10,9 @@
 // and is no more maintained or bugfixed, please update your go version
 // to at least 1.10 to get the latest updates.
 
-// Supported versions on MacOSX
-// - any go version earlier than 1.8
-// - go1.8.x series from 1.8.0 to 1.8.6
-// - go1.9.x series from 1.9.0 to 1.9.3
-
-// Versions NOT supported on MacOSX
-// - go1.8.x series starting from 1.8.7
-// - go1.9.x series starting from 1.9.4
-
 package enumerator // import "go.bug.st/serial.v1/enumerator"
 
-// #cgo LDFLAGS: -framework CoreFoundation -framework IOKit -fconstant-cfstrings
+// #cgo LDFLAGS: -framework CoreFoundation -framework IOKit
 // #include <IOKit/IOKitLib.h>
 // #include <CoreFoundation/CoreFoundation.h>
 // #include <stdlib.h>