Problem: travis ignores "sourceline" aliases for prepackaged ZMQ stack

Solution: avoid a level of object nesting by removing the leading dash.
See testing at travis-ci/travis-ci#9693
Should solve #1188

Signed-off-by: Jim Klimov <[email protected]>

Author: jimklimov

zproject_travis.gsl

@@ -202,14 +202,17 @@ pkg_deps_doctools: &pkg_deps_doctools
 pkg_deps_devtools: &pkg_deps_devtools
     - git
 
+# NOTE: Unlike earlier zproject versions, the pkg_src* objects below do not
+# start with a dash, due to peculiarities of YAML alias dereferencing in Travis
+
 # dist==trusty means ubuntu14
 pkg_src_zeromq_ubuntu14: &pkg_src_zeromq_ubuntu14
-- sourceline: 'deb http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-draft/xUbuntu_14.04/ ./'
+  sourceline: 'deb http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-draft/xUbuntu_14.04/ ./'
   key_url: 'http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-draft/xUbuntu_14.04/Release.key'
 
 # dist==xenial means ubuntu16
 pkg_src_zeromq_ubuntu16: &pkg_src_zeromq_ubuntu16
-- sourceline: 'deb http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-draft/xUbuntu_16.04/ ./'
+  sourceline: 'deb http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-draft/xUbuntu_16.04/ ./'
   key_url: 'http://download.opensuse.org/repositories/network:/messaging:/zeromq:/git-draft/xUbuntu_16.04/Release.key'
 
 pkg_deps_common: &pkg_deps_common