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] <[email protected]>

Author: dependabot[bot]

requirements/dev.txt

@@ -3,7 +3,7 @@ ForgeryPy==0.1
 Pygments==2.2.0
 colorama==0.3.9
 coverage==4.4.1
-httpie==0.9.9
+httpie==1.0.3
 requests==2.20.0
 selenium==3.5.0
 unittest-xml-reporting==2.1.0