Fix failing CI (#12)

* Fix unit test command

* Use 9.4 image

* Use Swift 4

* Use destination instead

Author: chuganzy

.travis.yml

@@ -2,13 +2,13 @@
 # * http://www.objc.io/issue-6/travis-ci.html
 # * https://github.com/supermarin/xcpretty#usage
 
-osx_image: xcode8.2
+osx_image: xcode9.4
 language: objective-c
 # cache: cocoapods
 # podfile: Example/Podfile
 # before_install:
 # - gem install cocoapods # Since Travis is not always on latest version
 # - pod install --project-directory=Example
 script:
-- set -o pipefail && xcodebuild test -workspace Example/Fuse.xcworkspace -scheme Fuse-Example -sdk iphonesimulator9.3 ONLY_ACTIVE_ARCH=NO | xcpretty
+- set -o pipefail && xcodebuild build test -workspace Example/Fuse.xcworkspace -scheme Fuse-Example -destination 'platform=iOS Simulator,name=iPhone 6' ONLY_ACTIVE_ARCH=NO | xcpretty
 - pod lib lint

Fuse.podspec

@@ -14,4 +14,5 @@ Pod::Spec.new do |s|
 
   s.ios.deployment_target = '8.0'
   s.source_files = 'Fuse/Classes/**/*'
+  s.swift_version = '4.1.2'
 end