[2.0.2] - Changes expiration date's API

Makes isExpired return false when when there's no exp claim.
Makes both getExpirationDate and getRemainingTime return null when there's no exp claim.
Makes getTokenTime return null when there's no iat claim.

[2.0.1]

getRemainingTime() method

[2.0.0]

Migration to null safety
Updated SDK dependency version to 2.12.0+
Avoid all null returns and replaced them with FormatException throws when tokens are not valid. This is a breaking change as users expecting null returns will now get an exception instead.
Added JwtDecoder methods documentation.
Replaced flutter framework dependencies to Dart only dependency.

[1.0.4]

isExpired() and getExpirationDate() the expiration time is converted to int

[1.0.3]

getExpirationDate() returns the expiration date of the token
getTokenTime() you can use this method to know how old your token is

[1.0.2]

License was added

[1.0.1]

An example file was added

[1.0.0]

decode method will decode your token's payload and return a Map<String, dynamic>
isExpired method is used to know if a token is already expired or not