Removing VOEvent file text hack

Removing hack which includes the VOEvent file text in the response
for VOEvent gets and creation.  This has been deprecated for a few
months and users have had time to adapt to the necessity of
getting the file content separately.
6 jobs for superevents in 3 minutes and 18 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Build
passed #164064
build:debian:jessie

00:02:57

passed #164065
build:debian:stretch

00:01:12

passed #164063
build:el7

00:00:51

passed #164062
build:tarball

00:00:21

 
  Test
passed #164066
test:python2.7

00:00:18

passed #164067
test:python3.6

00:00:19