Switch to ginkgo/gomega for tests

This switches over to ginkgo/gomega for tests, which makes writing
certain tests easier/more fluent in the future.

vendor/github.com/hpcloud/tail/tail_posix.go

@@ -0,0 +1,11 @@
+// +build linux darwin freebsd netbsd openbsd
+
+package tail
+
+import (
+	"os"
+)
+
+func OpenFile(name string) (file *os.File, err error) {
+	return os.Open(name)
+}