Add travis file and reenable 'install deps' in magefile

.travis.yml

@@ -0,0 +1,13 @@
+language: go
+git:
+  depth: false
+go:
+  - 1.9.5
+  - "1.10.1"
+os:
+  - linux
+  - osx
+  - windows
+install:
+  - go get github.com/magefile/mage
+  - mage -v install

magefile.go

@@ -30,7 +30,7 @@ type target struct {
 
 // Build Builds swd and swdcli and moves it to the dist directory
 func Build() error {
-	//mg.Deps(InstallDeps)
+	mg.Deps(InstallDeps)
 	mg.Deps(Clean)
 
 	if _, err := os.Stat(DIST); os.IsNotExist(err) {
@@ -134,7 +134,7 @@ func Check() error {
 
 // Install Installs swd and swdcli to your $GOPATH/bin folder
 func Install() error {
-	//mg.Deps(InstallDeps)
+	mg.Deps(InstallDeps)
 
 	fmt.Println("Installing...")
 	return exec.Command("go", "install", "./...").Run()