v0.6.1

• fix version reporting (v0.6.0 erroneously reported as v0.5.0)

$ sha1sum dockviz_*
fc4919354f75c8cb3a07c7600fd468960b19efb7  dockviz_darwin_amd64
38f76d9ccd15e3e792dba13801e8c9f2079989a8  dockviz_linux_amd64
0ee94df431d6fccbfd9c5a3e79dc588341dc98b0  dockviz_linux_arm
$ sha256sum dockviz_*
99d4161f90977ef4152ae755f1773ff958c0997ae4477ef239f26f14c1e1647d  dockviz_darwin_amd64
697b587c4879c52ee9df8c1d8f7bb6731767d796df8a69b4992e1484a2e966e1  dockviz_linux_amd64
216cf50585591d994e46958a2e8f988d68fe11a2cc8c8dc0e995f69d8b725aa3  dockviz_linux_arm
$ md5sum dockviz_*
0223345fd62432443e4ba4db7f4ad838  dockviz_darwin_amd64
667f50b7ff45b4406af39860a3b81918  dockviz_linux_amd64
b74814e90e2aefdfbbf84842cc802c5c  dockviz_linux_arm