Reindent changes -1e-10 to be a string

[chrisranderson]

Given the file contents:

{"a": -1e-10}

Reindenting returns:

{
  "a": "-1e-10"
}

It should leave it as a number in scientific notation:

{
  "a": -1e-10
}

[willstott101]

Looks like this is due to using pyyaml to load json...

>>> json.loads("-1e-10")
-1e-10
>>> yaml.safe_load("-1e-10")
'-1e-10'

Here is the bug report in PyYAML: yaml/pyyaml#173