Update nitrokey crate to 0.4.0-alpha.3

This change updates the version of the nitrokey crate that we use to
0.4.0-alpha.3. This version is the supposedly last pre-release before
0.4.0, with no further major anticipated changes.
In order to integrate with this new version we have to adjust the way we
connect to a Nitrokey device by funneling those connection requests
through a global manager object. The rationale behind that step being
that the underlying libnitrokey actually cannot handle access of
multiple devices at the same time, and so the manager object is used to
prevent accidental wrong concurrent usage.
Because a device object now effectively keeps a reference to the
manager, we need to provide an additional lifetime to that and derived
objects.
Lastly, the use of a manager is also the reason why the tests had to be
adjusted to no longer accept device objects in their signatures, but
only the respective model for which to invoke the test. That is required
because, as elaborated earlier on, having a device object implies having
taken a reference to a manager (in that case owned by nitrokey-test),
and that reference clashes with the nitrocli code itself attempting to
take the manager. We side step this problem by merely accepting a Model
object, which can be passed around independently of the manager itself,
meaning that nitrokey-test does not need to hold such a reference while
the test is run.

Import subrepo nitrokey/:nitrokey at f150d59410eefdec2ae69b2422906a3d1d88aa07
Import subrepo nitrokey-sys/:nitrokey-sys at 8695e2c762807e033a86c8d03974b686d20cdd72
Import subrepo lazy-static/:lazy-static at b4b2b16aaa79dd7548e288455a0dbe4065bf4e1a

1 files changed, 10 insertions, 0 deletions

diff --git a/nitrokey/CHANGELOG.md b/nitrokey/CHANGELOG.md
index e98e857..3051d0f 100644
--- a/nitrokey/CHANGELOG.md
+++ b/nitrokey/CHANGELOG.md
@@ -38,6 +38,16 @@ SPDX-License-Identifier: MIT
   - Implement `DerefMut` for `User<T>` and `Admin<T>`.
   - Add `device_mut` method to `DeviceWrapper`.
   - Require a mutable `Device` reference if a method changes the device state.
+- Update the `nitrokey-sys` dependency to version 3.5.0.
+- Update the `nitrokey-test` dependency to version 0.3 and add the
+  `nitrokey-test-state` dependency in version 0.1.0.
+- Refactor connection management:
+  - Add `ConcurrentAccessError` and `PoisonError` `Error` variants.
+  - Add the `Manager` struct that manages connections to Nitrokey devices.
+  - Remove `connect`, `connect_model`, `Pro::connect` and `Storage::connect`.
+  - Add the `into_manager` function to the `Device` trait.
+  - Add the `force_take` function that ignores a `PoisonError` when accessing
+    the manager instance.
 
 # v0.3.4 (2019-01-20)
 - Fix authentication methods that assumed that `char` is signed.