Probably since #647 helmfile has been unable to merge nested maps in environment values if they were loaded from files. This fixes it.
The relevant test is also enhanced so that no further regression like this happens.
Fixes#677
Seems like we are affected by https://github.com/golang/go/issues/24963. That is, even though we internally use the template option `missingkey=zero`, in some cases it still prints `<no value>` instead of zero values, which has been confusing the state yaml parsing.
This fixes the issue by naively replacing all the remaining occurrences of `<no value>` in the rendered text, while printing debug logs to ease debugging in the future when there is unexpected side-effects introduced by this native method.
Fixes#553
KUOKA Yusuke