Fix 500 error because of incorrect parameter name
Select shellid from response using correct xpath
Return non-200 http results as errors to caller
Display errors to user on stdout

Also default user creds to vagrant
Can specify alternate port
Must specify port when creating WinRM Client
WinRM endpoint as a struct
Merge remote-tracking branch 'github/pr/3'

Conflicts:
	winrm.go
Merge pull request #4 from pdericson/develop

Merging PR #2 and PR #3