ci: Fix macOS build refactoring how setup.py args are passed

This commit clearly identifies CMake arguments and setuptools command
arguments.

This fixes error "error: option --plat-name not recognized" reported  by
sdist command.

Author: jcfr

scikit-ci.yml

@@ -12,15 +12,16 @@ before_install:
   circle:
     environment:
       PATH: /opt/python/$<MANYLINUX_PYTHON>/bin:$<PATH>
-      SETUP_ARGS: -- -DOPENSSL_ROOT_DIR:PATH=/usr/local/ssl
+      SETUP_CMAKE_ARGS: -DOPENSSL_ROOT_DIR:PATH=/usr/local/ssl
     commands:
       - rm -rf dist/*
 
   travis:
     osx:
       environment:
         PATH: $<HOME>/.pyenv/versions/$<PYTHON_VERSION>/bin:$<PATH>
-        SETUP_ARGS: --plat-name macosx-10.6-x86_64 -- -DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=10.6 -DCMAKE_OSX_ARCHITECTURES:STRING=x86_64 -DCMAKE_OSX_SYSROOT:PATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
+        SETUP_BDIST_WHEEL_ARGS: --plat-name macosx-10.6-x86_64
+        SETUP_CMAKE_ARGS: -DCMAKE_OSX_DEPLOYMENT_TARGET:STRING=10.6 -DCMAKE_OSX_ARCHITECTURES:STRING=x86_64 -DCMAKE_OSX_SYSROOT:PATH=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
       commands:
         - python ../addons/travis/install_pyenv.py
         - python ../addons/travis/install_cmake.py 3.6.2
@@ -38,8 +39,8 @@ before_build:
 
 build:
   commands:
-    - python setup.py --hide-listing sdist $<SETUP_ARGS>
-    - $<RUN_ENV> python setup.py --hide-listing bdist_wheel $<SETUP_ARGS>
+    - python setup.py --hide-listing sdist -- $<SETUP_CMAKE_ARGS>
+    - $<RUN_ENV> python setup.py --hide-listing bdist_wheel $<SETUP_BDIST_WHEEL_ARGS> -- $<SETUP_CMAKE_ARGS>
 
   circle:
     commands: