check that carthage build succeeds from travis

Author: JonasVautherin

.travis.yml

@@ -58,3 +58,4 @@ script:
   - make test-plugin
   - make test-echo
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then make xcodebuild; fi
+  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then travis_wait 30 make build-carthage; fi

Makefile

@@ -40,6 +40,9 @@ test-plugin:
 xcodebuild: project
 		xcodebuild -project SwiftGRPC.xcodeproj -configuration "Debug" -parallelizeTargets -target SwiftGRPC -target Echo -target Simple -target protoc-gen-swiftgrpc build
 
+build-carthage:
+	carthage build --no-skip-current
+
 clean:
 	rm -rf Packages
 	rm -rf .build build