Fix hub when a remote has local path instead of URL

Fixes #470
Prefer browsing upstream when on the master branch

When a user would do `hub browse` on the master branch and they had a
fork, the hub would open the browser with their fork instead of the
upstream project. This is surprising and unwanted, so I've added an
exception for this case.

Fixes #474
Go canonical when browsing to subpage other than commits/tree/blob/settings

If the user is currently on the "feature" branch that is pushed to their
fork, when they do `hub browse -- issues` it should open issues of the
main (canonical) repository, not that of the fork.
Merge branch 'browse-upstream'
v1.11.2
Disable CI email completely since configuration is not flexible

We can't let email configuration be the default since it would spam most
people in the GitHub org. However, we set it to a couple of addresses
explicitly, we get emailed with failures from other people's forks who
have set up CI for themselves.
Skip caching dependencies if Amazon secret is unavailable

Fixes CI in forked environment and enables usage of `cached-bundle`
script to just restore caches from S3 but never attempt to write them.
Merge branch 'forked-ci'
Validate that HTTPS is used by default for API requests

Since we use a test server representing the GitHub API, all requests get
transformed to HTTP in tests. Make a check that the original requests
really was intended to go over HTTPS.