CI: Update travis for go1.10
CI: Update travis for go1.10

Add golang version 1.10 to the list of go versions tested under
TravisCI.

Note that the version needs to be quoted to ensure it isn't seen as
`1.1`.

Signed-off-by: James O. D. Hunt <348fbaadfbada55ea105602bf5609e23ac1c4898@intel.com>

dlespiau/covertool,dlespiau/covertool