Bump httpie from 0.9.9 to 1.0.3 in /requirements

Bumps [httpie](https://github.com/jakubroztocil/httpie) from 0.9.9 to 1.0.3.
- [Release notes](https://github.com/jakubroztocil/httpie/releases)
- [Changelog](https://github.com/jakubroztocil/httpie/blob/master/CHANGELOG.rst)
- [Commits](httpie/cli@0.9.9...1.0.3)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements/dev.txt

@@ -3,7 +3,7 @@ certifi==2017.7.27.1
 chardet==3.0.4
 coverage==4.4.1
 faker==0.7.18
-httpie==0.9.9
+httpie==1.0.3
 idna==2.5
 Pygments==2.2.0
 requests==2.18.2