build with jsoninter

[arun0009]

Allowing users to replace default encoding/json with jsoniter and build binary by using build tags(Instructions added to README).

Resolves:
#1698
#1204

[aldas]

Not really sure if it is the best solution.

Underlying problem is that currently library user does not have way to choose JSON implementation by themselves (centrally). They may not even be interested in json = jsoniter.ConfigCompatibleWithStandardLibrary as I would assume the reason for using different implementation (whether jsoninter or not) is performance gains over "StandardLibrary-like" implementations.

Maybe it would be better just change all places where encoders/decoders are created with calls to functions (on that object) that return json encoder/decoder needed and user is able to replace this Echo defaultJSONsomething with their own choosing.

That way we would not depend another library (and their problems/vulnerabilities)

[arun0009]

@aldas - I like the idea of default json and a way to override it with anything user can pass when configuring echo. This way we don't have to include additional libraries into echo.

[pafuent]

Maybe it would be better just change all places where encoders/decoders are created with calls to functions (on that object) that return json encoder/decoder needed and user is able to replace this Echo defaultJSONsomething with their own choosing.

I agree, it sounds a simpler solution that will give more freedom to Echo users, and will be less headaches for us 😉

[aldas]

I am closing this PR and we will be merging #1880 to allow different implementations