Update .travis.yml

Author: phimage

.travis.yml

@@ -11,7 +11,7 @@ env:
     - MACOS_SDK=macosx10.14
   matrix:
     - DESTINATION="OS=12.0,name=iPhone 8" SCHEME="$IOS_FRAMEWORK_SCHEME" SDK="$IOS_SDK" RUN_TESTS="NO"
-    - DESTINATION="arch=x86_64" SCHEME="$MACOS_FRAMEWORK_SCHEME" SDK=macosx10.13 RUN_TESTS="NO"
+    - DESTINATION="arch=x86_64" SCHEME="$MACOS_FRAMEWORK_SCHEME" SDK="$MACOS_SDK" RUN_TESTS="NO"
 before_install:
   - gem install xcpretty --no-rdoc --no-ri --no-document --quiet
 script: