Fix retry session info request

When fetching session info, the client would not retry in cases where
the request was successfully sent but no response was received.

This change only impacts BLE, since HTTP requests are synchronous.

Allow non-NIST-P256 TLS server keys

Fixes a regression in a safety check on the TLS key that prevented the
HTTP proxy server from launching.

The intended purpose of the safety check is to verify that the user is
not using the same key as both a TLS server key and a
command-authentication key. The code tries to load the TLS key as a
command-authentication key, and then compares it with the actual
command-authentication key. If the loading step fails because the TLS
key is not a NIST-P256 key, then everything is fine. There's no way it
could be being misued. However, a loading failure was being treated as a
fatal error.

Fix session info error handling

The vehicle sends unsolicited session info when it detects a possible
desync with the client, and so the client checks for session info on
each message it receives before passing it down the stack. However, the
session info mesasge in question could contain a "Key Not Paired" error,
and the client would continue trying to process session info messages
that contained this error.

bump version for vehicle command

bump version to publish docker image (#319)

bump version to v0.2.0 so first docker image is pushed (#301)

Update user agent version to v0.1.0

This change affects the default user agent version in HTTP requests and
anticipates a github tag update to the same version.

Spelling fixes

"Recieve" -> "Receive". D'oh!

The pkg/connector/ble/ble.go method had both Receive and Recieve
methods. Deleting the latter is an API-breaking change, but such changes
should be expected in v0.x.x according to Go semantic versioning
standards.

vehicle-command: Initial release