Update CircleCI to use Node v12

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   install:
     macos:
-      xcode: "10.3.0"
+      xcode: "11.2.1"
     working_directory: ~/repo
     steps:
       - checkout
@@ -26,7 +26,7 @@ jobs:
 
   test:
     macos:
-      xcode: "10.3.0"
+      xcode: "11.2.1"
     steps:
       - checkout
       - attach_workspace:
@@ -37,7 +37,7 @@ jobs:
 
   build:
     macos:
-      xcode: "10.3.0"
+      xcode: "11.2.1"
     steps:
       - checkout
       - attach_workspace:
@@ -54,7 +54,7 @@ jobs:
 
   release:
     macos:
-      xcode: "10.3.0"
+      xcode: "11.2.1"
     steps:
       - checkout
       - attach_workspace:

.travis.yml

@@ -6,7 +6,7 @@ language: node_js
 matrix:
   include:
     - os: linux
-      node_js: 12.10.0
+      node_js: 12
       env: CC=clang CXX=clang++ npm_config_clang=1
       compiler: clang