Allow building in docker by removing .git from .dockerignore

[peterbroadhurst]

If you currently try and do make in Docker, including the unit tests, it fails because the .git history is not there so the linter doesn't know when the last change was to apply the copyright building correctly:

�[0minternal/log/log.go:1:17: Expected:2022, Actual: 2021 Kaleido, Inc. (goheader)
// Copyright © 2021 Kaleido, Inc.
                ^
internal/i18n/errors.go:1:17: Expected:2022, Actual: 2021 Kaleido, Inc. (goheader)
// Copyright © 2021 Kaleido, Inc.
                ^
internal/i18n/messages.go:1:17: Expected:2022, Actual: 2021 Kaleido, Inc. (goheader)
// Copyright © 2021 Kaleido, Inc.
                ^
�[91mlevel=info msg="File cache stats: 325 entries of total size 1.2MiB"
level=info msg="Memory: 826 samples, avg is 225.0MB, max is 276.1MB"
level=info msg="Execution took 1m22.599796017s"
�[0m�[91mmake: *** [Makefile:21: lint] Error 1
�[0mThe command '/bin/sh -c make' returned a non-zero code: 2