1.3.1:
Make the map in MergeConfigMap case insensitive
1.3.0:
Restrict Travis to >= Go 1.11, use Go Modules, and get the test to pass
1.1.0:
* Added a new `DecoderConfigOption` type allowing the user to write custom
functions that can override the default mapstructure.DecoderConfig
settings
* Added a new `DecodeHook` function which returns
a `DecoderConfigOption`. This allows the user to easily set their own
Decode hooks when Unmarshaling
* Updated Unmarshal, UnmarshalKey and defaultDecoderConfig to support variadic
trailing `DecoderConfigOption` functions to allow for customisation of
the default mapstructure.DecoderConfig
* Added a test case with example usage
