authenticate: use gRPC for service endpoints (#39)

* authenticate: set cookie secure as default.
* authenticate: remove single flight provider.
* authenticate/providers: Rename “ProviderData” to “IdentityProvider”
* authenticate/providers: Fixed an issue where scopes were not being overwritten
* proxy/authenticate : http client code removed.
* proxy: standardized session variable names between services.
* docs: change basic docker-config to be an “all-in-one” example with no nginx load.
* docs:  nginx balanced docker compose example with intra-ingress settings.
* license:  attribution for adaptation of goji’s middleware pattern.

internal/cryptutil/encrypt.go

@@ -38,7 +38,7 @@ type XChaCha20Cipher struct {
 	aead cipher.AEAD
 }
 
-// NewCipher returns a new XChacha20poly1305 cipher.
+// NewCipher takes secret key and returns a new XChacha20poly1305 cipher.
 func NewCipher(secret []byte) (*XChaCha20Cipher, error) {
 	aead, err := chacha20poly1305.NewX(secret)
 	if err != nil {