Use http.Header, which is more descriptive on intent, and we're already
importing the package in the client. Removing the "header" type also fixes
various locations where the type was shadowed by local variables named
"headers".
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Since Go 1.7, context is a standard package. Since Go 1.9, everything
that is provided by "x/net/context" is a couple of type aliases to
types in "context".
Many vendored packages still use x/net/context, so vendor entry remains
for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
