Add F# headers to tests

Author: pbiggar

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-br.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH
 

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-compress.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH
 

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-deflate.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH
 

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-gzip.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH
 

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-identity.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH
 

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-many.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH
 

fsharp-backend/tests/httptestfiles/request-header-accept-encoding-star.test

@@ -19,6 +19,7 @@ access-control-allow-origin: * // OCAMLONLY
 x-darklang-execution-id: 0123456789
 Server: nginx/1.16.1 // OCAMLONLY
 Server: darklang // FSHARPONLY
+Vary: Accept-Encoding // FSHARPONLY
 Connection: keep-alive // OCAMLONLY
 Content-Length: LENGTH