Add Sierra compatibility note

.travis.yml

@@ -1,16 +1,21 @@
 language: objective-c
 
 os: osx
-osx_image: xcode9.3beta
+
+matrix:
+  include:
+    - osx_image: xcode9.3beta # macOS 10.13
+    - osx_image: xcode9.2     # macOS 10.12
 
 script:
   - xcodebuild -project Thunderbolt3Unblocker.xcodeproj -scheme Thunderbolt3Unblocker -configuration Release CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO SYMROOT=./build
+  - sudo chown -R root:wheel ./build/Release/Thunderbolt3Unblocker.kext
+  - sudo kextutil -nt build/Release/Thunderbolt3Unblocker.kext
 
 # It would be nice to subsequently load and test the kernel extension, but this
 # is not currently possible on Travis CI.
 #
 # Note that the kext runs xnu_override_test on load, and will fail the kextload
 # if the command fails. (That, or the system will panic.)
 # 
-# - sudo chown -R root:wheel ./build/Release/Thunderbolt3Unblocker.kext
 # - sudo kextload ./build/Release/Thunderbolt3Unblocker.kext

README.md

@@ -14,8 +14,9 @@ the patch in memory and on-the-fly.
 Note there is likely a reason why IOThunderboltFamily considers a peripheral
 unsupported in the first place. Use at your own peril.
 
-This kernel extension was last tested against macOS High Sierra 10.13.4. Please
-check for [open issues][issues] before using on newer versions.
+This kernel extension was last tested against macOS High Sierra 10.13.4 and 
+macOS Sierra 10.12.6. Please check for [open issues][issues] before using on
+other versions.
 
 [issues]: https://github.com/rgov/Thunderbolt3Unblocker/issues