Update appium-dotnet-driver.nuspec

update release notes
Fixed #48 (GetScreenshot method missing)
Added StartActivity method and tests.  Corrected package references to Newtonsoft.Json and Selenium.Webdriver.
Normalized line ending settings to Windows.
Update appium-dotnet-driver.csproj

updated location of projects
Update samples.csproj

updated location of nuget packages
Update README.md

update version number
Update RELEASE_NOTES.md
Update RELEASE_NOTES.md
add IsLocked

fixed #47