Refactor buck external dependencies

Change-Id: Ia4b99493407eb7d4e893804cba6b944f758f085e
diff --git a/incubator/api/BUCK b/incubator/api/BUCK
index 55f80e0..eb7b036 100644
--- a/incubator/api/BUCK
+++ b/incubator/api/BUCK
@@ -1,5 +1,6 @@
 COMPILE_DEPS = [
     '//lib:CORE_DEPS',
+    '//lib:JACKSON',
 ]
 
 TEST_DEPS = [