[ci] only run 'python setup.py test'

if we run 'python setup.py built test', the setuptools 'test' command will
forcibly re-run the build_ext subcommand because it wants to pass the --inplace
option (it ignores whether it's up to date, just re-runs it all the time).

with this we go from running built_ext twice, to running it only once per build

scripts/.travis.sh

@@ -45,7 +45,7 @@ case "$1" in
 		ctest -V
 		;;
 	    "python")
-		python setup.py build test
+		python setup.py test
 		;;
 	    "maven")
 		cd java/org/brotli

scripts/appveyor.yml

@@ -72,4 +72,4 @@ build_script:
 
 test_script:
   - if "%BUILD_SYSTEM%" == "CMake" ( ctest --output-on-failure --interactive-debug-mode 0 -C Debug )
-  - if "%BUILD_SYSTEM%" == "Python" ( python setup.py build test )
+  - if "%BUILD_SYSTEM%" == "Python" ( python setup.py test )