fix(travis): windows build hangs after exited with 0

Author: breeze2

.travis.yml

@@ -1,6 +1,6 @@
 env:
-  - SENTRY_RELEASE=$TRAVIS_TAG
-  - YARN_GPG=no
+  global:
+    - SENTRY_RELEASE=$TRAVIS_TAG
 
 matrix:
   include:
@@ -10,6 +10,7 @@ matrix:
       node_js: lts/*
       if: tag IS present
     - os: windows
+      env: YARN_GPG=no
       language: node_js
       node_js: lts/*
       if: tag IS present