Move to Go 1.10

[zjs]

Use Go 1.10 to compile the product. Update build image and Makefile accordingly. Fix unit tests which broke as a result of the upgrade.

Additionally, update dependencies so that build image can be built and clean up some modified tests.

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Contains portions of #7610.

Fixes: #7609

[full ci]

[wjun]

CI looks still broken?

[zjs]

CI looks still broken?

CI won't run until I push an updated integration testing docker image (v1.49) with the changes in this PR. However, I don't want to push a new version of the image to the production registry until someone has done at least some basic review of the changes.

[wjun]

LGTM.

[zjs]

This upgrade seems to change how SSL certificates are validated. Specifying a thumbprint is no longer sufficient to overcome certificate validation issues, such as those related to the use of self-signed certificates without IP SANs (resulting in error messages like Post https://10.192.207.166/sdk: x509: cannot validate certificate for 10.192.207.166 because it doesn't contain any IP SANs).

This is especially problematic for commands like vic-machine ls, which support --thumbprint, but not --force.

This is likely related to this note in the 1.10 release notes: https://golang.org/doc/go1.10#crypto/x509