1.1.0: exclude inner field if no inner error provided

Previous versions of this error strategy would define an inner property on all returned errors - even if the value was undefined. v1.2.0 will no longer define an inner property if an inner error is not specified.

The existence of inner property with an undefined value was resulting in confusing test assertions.

v1.0.0: Initial Release

package: set version to 1.0.0