add appveyor yml

Shodan.Net.sln

@@ -8,6 +8,7 @@ EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{18A95621-2E1B-48F0-9D38-D7B3513F31D3}"
 	ProjectSection(SolutionItems) = preProject
 		.gitignore = .gitignore
+		appveyor.yml = appveyor.yml
 		global.json = global.json
 		LICENSE.txt = LICENSE.txt
 		Readme.md = Readme.md

appveyor.yml

@@ -0,0 +1,13 @@
+version: 1.0.{build}
+configuration: Release
+before_build:
+- ps: >-
+    (new-object net.webclient).DownloadFile('https://download.microsoft.com/download/4/6/1/46116DFF-29F9-4FF8-94BF-F9BE05BE263B/packages/DotNetCore.1.0.0.RC2-SDK.Preview1-x64.exe','core.exe')
+
+    core.exe /install /quiet /norestart
+
+    dotnet restore
+build:
+  verbosity: minimal
+test_script:
+- cmd: dotnet test .\src\Shodan.Net.UnitTests\