meek-client tests failing

I think for one, it looks like copyPublicFields never got added and/or the TestCopyPublicFieldsHTTPTransport test is no longer necessary?

Additionally, the TestProxyHTTPSCONNECT seems to be failing with this output:

❯ go test . -v
=== RUN   TestMakeProxySpec
--- PASS: TestMakeProxySpec (0.00s)
=== RUN   TestAddrForDial
--- PASS: TestAddrForDial (0.00s)
=== RUN   TestProxyHTTPCONNECT
--- PASS: TestProxyHTTPCONNECT (0.00s)
=== RUN   TestProxyHTTPProxyAuthorization
--- PASS: TestProxyHTTPProxyAuthorization (0.00s)
=== RUN   TestProxyHTTPSCONNECT
    proxy_test.go:95: local error: tls: unexpected message
--- FAIL: TestProxyHTTPSCONNECT (0.01s)
panic: remote error: tls: unexpected message [recovered]
	panic: remote error: tls: unexpected message

goroutine 18 [running]:
testing.tRunner.func1.2(0x7d9200, 0xc0000203c0)
	/usr/local/go/src/testing/testing.go:1144 +0x332
testing.tRunner.func1(0xc00008a300)
	/usr/local/go/src/testing/testing.go:1147 +0x4b6
panic(0x7d9200, 0xc0000203c0)
	/usr/local/go/src/runtime/panic.go:965 +0x1b9
git.torproject.org/pluggable-transports/meek.git/meek-client.TestProxyHTTPSCONNECT(0xc00008a300)
	/home/maxb/work/tor/meek/meek-client/proxy_test.go:232 +0x3ec
testing.tRunner(0xc00008a300, 0x847030)
	/usr/local/go/src/testing/testing.go:1194 +0xef
created by testing.(*T).Run
	/usr/local/go/src/testing/testing.go:1239 +0x2b3
FAIL	git.torproject.org/pluggable-transports/meek.git/meek-client	0.021s
FAIL