Reduce testing

Author: Mark Kittisopikul

.travis.yml

@@ -26,10 +26,17 @@ jobs:
     env: JULIA_COPY_STACKS=0 JAVACALL_FORCE_ASYNC_INIT=1
   - julia: 1.0
     env: JULIA_COPY_STACKS=0 JAVACALL_FORCE_ASYNC_TEST=1
+  - os: mac
+    env: JULIA_COPY_STACKS=0 JAVACALL_FORCE_ASYNC_INIT=1
+  - os: mac
+    env: JULIA_COPY_STACKS=0 JAVACALL_FORCE_ASYNC_TEST=1
   - os: windows
     env: JULIA_COPY_STACKS=0 JAVACALL_FORCE_ASYNC_INIT=1
   - os: windows
     env: JULIA_COPY_STACKS=0 JAVACALL_FORCE_ASYNC_TEST=1
+  - julia: 1.0
+    os: windows
+    env: JULIA_COPY_STACKS=1
   allow_failures:
   - julia: nightly
   - os: windows