Upgrade unirest to version 4

[frankgiordano]

Upgrade third party package unirest to version 4. Initially this SDK used Apache commons for http processing and then we migrated to unirest version 3.x.

The upgrade keeps in pace with unirest latest developments.

unirest version 4 removes reliance on its usage of Apache for some http processing.

In addition, version 4 provides the feature for cookie processing within a http call. This is needed for zosmfauth package being worked on in MVP #4.

[frankgiordano]

Noticed an issue with new unirest. It doesn't provide status text information on http error processing like version 3 did.

With version 3 of unirest, a http request with invalid username/password the following will be returned:

http status error code: 401, status text: Unauthorized, response phrase: {}

With the current version 4.x it returns:

http status error code: 401, status text: , response phrase: {}

The "Unauthorized" is missing.

I also see less information being returned when a bad hostname is specified:

version 3:

java.net.UnknownHostException: No such host is known (xxxx.xxx.xxx.xx)

version 4.x:

java.net.ConnectException

[frankgiordano]

I've opened an issue with unirest project, inquiring about the "status text" behavior.

Kong/unirest-java#539

Before, Apache commons were relied on within unirest and the latest version of unirest removes all Apache usage and I believe that is the cause. It isn't something that is necessary for unirest or any http library to provide further information within the "status text" but it would have been nice.

I might have to change the code within ZosmfRequest.java method buildResponse() in this project to handle the interpretation of http error code into "status text" explanation. unirest has a good definition layout that I can piggy back on for our own interpretation processing.

https://github.com/Kong/unirest-java/blob/2af241ab501e473de57ac450e7a674be3df930b5/unirest/src/main/java/kong/unirest/core/HttpStatus.java#L48

[frankgiordano]

I made changes to work around the empty status text returned. I've introduced a map of values to query status code and return text representation and use that as a status text.