Update numpy from 1.14.0 to 1.14.1

requirements.txt

 Dijkstar==2.4.0
 freezegun==0.3.9
 future==0.16.0
-numpy==1.14.0
+numpy==1.14.1
 pluggy==0.6.0
 psutil==5.4.3
 py==1.5.2