Merge remote-tracking branch 'origin/master' into release/0.1

Author: seemethere

.circleci/config.yml

@@ -157,7 +157,7 @@ jobs:
   binary_macos_wheel:
     <<: *binary_common
     macos:
-      xcode: "9.0"
+      xcode: "9.4.1"
     steps:
       - checkout_merge
       - run:
@@ -179,7 +179,7 @@ jobs:
   binary_macos_conda:
     <<: *binary_common
     macos:
-      xcode: "9.0"
+      xcode: "9.4.1"
     steps:
       - checkout_merge
       - run: