Drop pyton-future depends

This is only required for Python < 3

.SRCINFO

 pkgbase = python-commonmark
 	pkgdesc = Python parser for the CommonMark Markdown spec
 	pkgver = 0.9.1
-	pkgrel = 10
+	pkgrel = 11
 	url = https://pypi.org/project/commonmark/
 	arch = any
 	license = BSD
@@ -13,7 +13,6 @@ pkgbase = python-commonmark
 	makedepends = python-sphinx
 	makedepends = python-sphinx_rtd_theme
 	depends = python-docutils
-	depends = python-future
 	options = !makeflags
 	source = python-commonmark-0.9.1.tar.gz::https://github.com/readthedocs/commonmark.py/archive/0.9.1.tar.gz
 	sha256sums = b5d5be6af35a183c3f915d714b31b61e6918894051114419f9ac0bbb715bf4c6

PKGBUILD

@@ -3,13 +3,12 @@
 
 pkgname=python-commonmark
 pkgver=0.9.1
-pkgrel=10
+pkgrel=11
 pkgdesc='Python parser for the CommonMark Markdown spec'
 url='https://pypi.org/project/commonmark/'
 arch=('any')
 license=('BSD')
-depends=('python-docutils'
-         'python-future')
+depends=('python-docutils')
 makedepends=('python-'{build,installer,wheel}
              'python-setuptools'
              'python-sphinx'