Configs merge behavior in v 0.8.1 changed

[ArtemHarchishin]

Hello,
With new version 0.8.1, configs merge behavior changed.
Example:

import config

d = {
    "path": {
        "to": {
            "value-a": "A",
            "value-b": "B"
            }
        }
    }
base_cfg = config.config_from_dict(d)

d = {
    "path": {
        "to": {
            "value-a": "C"
            }
        }
    }
cfg = config.config_from_dict(d)

cfg_set = config.ConfigurationSet(cfg, base_cfg)

path_config = cfg_set.get('path')
print(path_config)
>>> {'to.value-a': 'C'}

in version 0.7.0 it print

>>> {'to.value-a': 'C', 'to.value-b': 'B'}

[Tiago Requeijo]

Sorry for the delay, I'll look into it -- the 0.7.xx behavior should be the correct one

[Ching-Hwa Yu]

@ArtemHarchishin I believe I've fixed this in #52.

[Tiago Requeijo]

@chinghwayu, thank you for the PR!