Update Python Cloud Debugger to v1.5

Author: vladlf

src/build.sh

@@ -29,7 +29,7 @@
 # The major version should only change on breaking changes. Minor version
 # changes go between regular updates. Instances running debuggers with
 # different major versions will show up as two different debuggees.
-__version__ = '1.4'
+__version__ = '1.5'
 
 _flags = None