If key and value are both quoted with the same character, leading equals sign in value gets strange

[nicktimko]

Some strange edge case probably, but pipenv kicks out strings like "flake8" = "==3.6.0" every so often which triggers it. Doesn't even seem like the GitHub formatter gets it right (some red highlighting on the keyb line for me...)

# nothing to see here
key = "value"
"keya" = "value"

# same quote types
"keyb" = "=value"
'keyc' = '=value'

# differing quote types for key/value
'keyd' = "=value"
"keye" = '=value'

Better TOML: 0.3.2 VSCode: 1.29.1 OS: Ubuntu 16.04