Bump numpy from 1.16.3 to 1.16.4

Bumps [numpy](https://www.numpy.org) from 1.16.3 to 1.16.4.

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

Author: dependabot-preview[bot]

requirements.txt

@@ -16,7 +16,7 @@ idna==2.8
 kiwisolver==1.1.0
 matplotlib==3.1.0
 more-itertools==7.0.0
-numpy==1.16.3
+numpy==1.16.4
 pandas==0.24.2
 pep8==1.7.1
 pkginfo==1.5.0.1