Fix `make clean` and switch to Carthage debug builds on CI for improved performance.

.travis.yml

@@ -57,4 +57,4 @@ script:
   - echo -en 'travis_fold:start:make.test-plugin\\r' && make test-plugin && echo -en 'travis_fold:end:make.test-plugin\\r'
   - echo -en 'travis_fold:start:make.test-echo\\r' && make test-echo && echo -en 'travis_fold:end:make.test-echo\\r'
   - echo -en 'travis_fold:start:make.xcodebuild\\r' && if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then make xcodebuild; fi && echo -en 'travis_fold:end:make.xcodebuild\\r'
-  - echo -en 'travis_fold:start:make.build-carthage\\r' && if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then make clean && travis_wait 40 make build-carthage; fi && echo -en 'travis_fold:end:make.build-carthage\\r'
+  - echo -en 'travis_fold:start:make.build-carthage\\r' && if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then make clean && travis_wait 40 make build-carthage-debug; fi && echo -en 'travis_fold:end:make.build-carthage\\r'

Makefile

@@ -44,11 +44,15 @@ xcodebuild: project
 build-carthage:
 	carthage build --no-skip-current
 
+build-carthage-debug:
+	carthage build --no-skip-current --configuration Debug --platform iOS, macOS
+
 clean:
 	-rm -rf Packages
 	-rm -rf .build build
 	-rm -rf SwiftGRPC.xcodeproj
 	-rm -rf Package.pins Package.resolved
 	-rm -rf protoc-gen-swift protoc-gen-swiftgrpc
-	-cd Examples/Echo/PackageManager && make clean
-	-cd Examples/Simple/PackageManager && make clean
+	-cd Examples/Google/Datastore && make clean
+	-cd Examples/Google/NaturalLanguage && make clean
+	-cd Examples/Google/Spanner && make clean