Update CHANGELOG

Author: morgante

CHANGELOG.md

@@ -1,20 +1,26 @@
-## 0.4.0
+## [Unreleased]
+### Fixed
+- Resolved issue with networks that have no secondary networks (#19)
 
+## 0.4.0
+### Changed
 - Make `subnet_private_access` and `subnet_flow_logs` into strings to be consistent with `shared_vpc` flag (#13)
 
 ## 0.3.0
-
+### Added
 - Add support for controlling subnet flow logs (#6)
+
+### Changed
 - Make `subnet_private_access` default to false (#6)
 
 ## 0.2.0
-
+### Added
 - Add support for Shared VPC hosting
 
 ## 0.1.0
 
-This is the initial release of the module, with basic support for creating:
-
+### Added
+- Initial release
 - A Google Virtual Private Network (VPC)
 - Subnets within the VPC
 - Secondary ranges for the subnets (if applicable)