py2.7.5 compatibility fix

10 jobs for gracedb-2.6.1 in 4 minutes and 37 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #834382
build:debian:jessie

00:03:07

passed #834383
build:debian:stretch

00:01:33

passed #834381
build:el7

00:01:15

passed #834380
build:tarball

00:00:29

 
  Test
passed #834388
docs

00:01:28

passed #834389
syntax

00:00:53

passed #834384
test:python2.7

00:00:49

84.0%
passed #834385
test:python3.5

00:00:52

84.0%
passed #834386
test:python3.6

00:01:01

84.0%
passed #834387
test:python3.7

00:00:48

84.0%