Merge pull request #47 from ramittal/master

Merging latest api changes and few bug fixes
Fixing travis url
Fix typo found in multiple tests
Merge pull request #50 from billboyde/future

Fix typo found in multiple tests
Added documentation reference to NUnit
adding reference to NUnit
Fixing credentials placeholders
Merge pull request #52 from ramittal/master

Merge handling of schema validation errors
Create .gitignore
Merged bojake PR into future
Merge branch 'bojake-master' into future
Update .gitignore
bumped up the version
fixed README.md
Merge pull request #1 from arktseytlin/future

Pulling changes
Added back a helper method that was lost after initial refactor
Merge branch 'future' of https://github.com/AuthorizeNet/sdk-dotnet into future
Merge pull request #54 from arktseytlin/master

Bumped up SDK version; minor defect fixes
Merge pull request #55 from ramittal/master

Adding missing required properties for paypal
Merge pull request #56 from AuthorizeNet/future

1.8.3 Release into Master