Unable to Parse Private Key Using New()

Hi, I am trying to use the New() method to create a transport for use in my github client, but I am having trouble with my RSA key being parsed. When I used NewKeyFromFile() everything worked fine, but swapping to New() and feeding in a string of the key as a byte gives me the following error: could not parse private key: Invalid Key: Key must be PEM encoded PKCS1 or PKCS8 private key. I am confused by this because in transport_test.go you are doing it the exact same way and I have to assume the tests are passing. I'm not sure if this is an issue in ghinstallation or go-github. Am I missing something?

key declaration: https://github.com/bradleyfalzon/ghinstallation/blob/d680810648e94347929da00376d1e7067f3572dd/transport_test.go#L27-L53
using key in New(): https://github.com/bradleyfalzon/ghinstallation/blob/d680810648e94347929da00376d1e7067f3572dd/transport_test.go#L167

My code is like this:

var key = `-----BEGIN RSA PRIVATE KEY-----
KEY GOES HERE
-----END RSA PRIVATE KEY-----`

itr, err := ghinstallation.New(
        http.DefaultTransport,
        99,
        123,
        []byte(key),
)
if err != nil {
log.Fatal("github authentication error: ", err)
}
githubClient := github.NewClient(&http.Client{Transport: itr})

bradleyfalzon / ghinstallation

Unable to Parse Private Key Using New() #126