feat: Intel AMT driver over WS-Management (0.1.0)

An `amt` driver (napalm_amt.AmtDriver), a ManagementControllerDriver for the
management controller of Intel vPro machines, with its own lean WS-Management
client (requests + ElementTree, HTTP Digest, ports 16992/16993).

It reads the machine's identity, hardware with the SMBIOS system UUID, firmware
(AMT with build, BIOS), power state and the hardware event log, reports what AMT
listens on (plain HTTP or TLS, KVM incl. port 5900, IDE-R), and switches the
machine's power. AMT cannot be reset over WS-Management, so there is no
reboot_host. Discovery recognises AMT by its ports and its Server header.

Tested against Intel's published AMT 12 recordings (go-wsman-messages,
Apache-2.0, see NOTICE). `python -m napalm_amt.record` records a real AMT
read-only; the first test devices are two Lenovo ThinkCentre M910x.

CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+
+## 0.1.0
+
+- `amt` driver (`napalm_amt.AmtDriver`), a `ManagementControllerDriver` for Intel AMT over
+  WS-Management: facts, AMT's network port, hardware inventory with the SMBIOS system
+  UUID, firmware (AMT with build, BIOS), power state and power control, the hardware event
+  log, and what AMT listens on (plain HTTP or TLS, KVM, virtual media).
+- Discovery: ports 16992/16993 and AMT's name in the `Server` header and web UI.
+- `python -m napalm_amt.record`: records a real AMT's answers as fixtures, read-only.