Sign mac app (#136)

sign_mac_app.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# thanks to https://www.jviotti.com/2016/03/16/how-to-code-sign-os-x-electron-apps-in-travis-ci.html
+# for the helpful instructions
+if [[ "$SHOULD_BUILD" == "yes" ]]; then
+  if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
+    if [ -d "VSCode-darwin" ]; then # just in case the build failed
+      cd VSCode-darwin
+      export CERTIFICATE_P12=VSCodium.p12
+      echo $CERTIFICATE_OSX_P12 | base64 --decode > $CERTIFICATE_P12
+      export KEYCHAIN=build.keychain
+      security create-keychain -p mysecretpassword $KEYCHAIN
+      security default-keychain -s $KEYCHAIN
+      security unlock-keychain -p mysecretpassword $KEYCHAIN
+      security import $CERTIFICATE_P12 -k $KEYCHAIN -P $CERTIFICATE_OSX_PASSWORD -T /usr/bin/codesign
+      
+      # https://docs.travis-ci.com/user/common-build-problems/
+      security set-key-partition-list -S apple-tool:,apple: -s -k mysecretpassword $KEYCHAIN
+      
+      codesign --deep --force --verbose --sign "$CERTIFICATE_OSX_ID" VSCodium.app
+    fi
+  fi
+fi