Handle cli values that might be interpreted as scientific notation

[dcernag]

k8t CLI accepts json to be sent via --values to accommodate nested values. json.loads in util.load_cli_values would parse strings matching scientific notation to float even if it is a string.

This was first found when a 77950e8 commit sha sent as a CLI value was parsed as 7795000000000.0

See default decoding in https://docs.python.org/3/library/json.html#json-to-py-table

Temporary emergency fix added in #95 , we need to find a better way to handle them.