63 - SPanel Implementation

[RoussKS]

Closes #63

Implementation for SPanel based on original PR #61

Branched off to new branch and make necessary fixes as described in the comments #61 (review)

Tested all methods as described in the original PR

The following operations are implemented for SPanel:

create()
getInfo()
getUsage()
getLoginUrl() - returns a link to https://hostname/spanel/login
changePassword()
changePackage()
suspend()
unSuspend()
terminate()

The following operations aren't supported by SPanel:

grantReseller()
revokeReseller()

Important

Once approved and merged, delete the branch feature/63-spanel of the original PR