Merge pull request #1 from jhendrixMSFT/master

Add constants for user agent and version info.

pipeline/version.go

@@ -0,0 +1,9 @@
+package pipeline
+
+const (
+	// UserAgent is the string to be used in the user agent string when making requests.
+	UserAgent = "azure-pipeline-go/" + Version
+
+	// Version is the semantic version (see http://semver.org) of the pipeline package.
+	Version = "0.1.0"
+)