Release google-api-core 1.3.0 (#5700)

diff --git a/setup.py b/setup.py
index 5a6d0ec..b813a18 100644
--- a/setup.py
+++ b/setup.py
@@ -22,7 +22,7 @@
 
 name = 'google-api-core'
 description = 'Google API client core library'
-version = '1.2.1'
+version = '1.3.0'
 # Should be one of:
 # 'Development Status :: 3 - Alpha'
 # 'Development Status :: 4 - Beta'