fix(package): nuspec was invalid

Author: richardschneider

src/IpfsApi.nuspec

@@ -1,4 +1,8 @@
-<?xml version="1.0" e
+<?xml version="1.0" encoding="utf-8"?>
+<package xmlns="http://schemas.microsoft.com/packaging/2011/08/nuspec.xsd">
+  <metadata>
+    <id>Ipfs.Api</id>
+    <version>$version$</version>
     <title>IPFS API</title>
     <authors>Richard Schneider</authors>
     <owners>Richard Schneider</owners>