Exclude header org-babel execution

Fixes #3

Introduces a new header argument to show the header information from the
HTTP request. Header information is off by default and can be turned on
by adding `:header yes` to the src-block header.
Merge branch 'master' into feature/exclude-header-in-org

Conflicts:
	es-mode.el
Remove all successful headers

It is only success code 200 that respond with OK.
fix wrong suggestion when asking for url
move function to more appropriate position
use es-endpoint-url if set
Merge pull request #7 from dakrone/feature/exclude-header-in-org

Exclude header org-babel execution