Travis merge jobs use custom-compiled PostgreSQL

With this commit, we start to use custom compiled PostgreSQL builds in
Travis for merge commits. This allows us to run isolation tests and
PostgreSQL's own regression tests along with our regression tests in
Travis.

Since manually compiling PostgreSQL takes more time and we also add new
tests, we only enable running these tests on merge commits.

.travis.yml

@@ -8,11 +8,13 @@ env:
   global:
     # GitHub API token for citus-bot
     - secure: 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
+    # During pull request builds (not push builds), use custom-built PostgreSQL
+    - USE_CUSTOM_PG="${TRAVIS_PULL_REQUEST_SHA}"
   matrix:
     - PGVERSION=9.5
     - PGVERSION=9.6
 before_install:
-  - git clone -b v0.5.1 --depth 1 https://github.com/citusdata/tools.git
+  - git clone -b v0.6.1 --depth 1 https://github.com/citusdata/tools.git
   - sudo make -C tools install
   - setup_apt
   - curl https://install.citusdata.com/community/deb.sh | sudo bash
@@ -20,7 +22,9 @@ before_install:
 install:
   - install_uncrustify
   - install_pg
-  - sudo apt-get install -y "postgresql-${PGVERSION}-hll=2.10.1.citus-1"
+  - install_custom_pg
+  # download and install HLL manually, as custom builds won't satisfy deps
+  - apt-get download "postgresql-${PGVERSION}-hll=2.10.1.citus-1" && sudo dpkg --force-confold --force-confdef --force-all -i *hll*.deb
 before_script: citus_indent --quiet --check
 script: CFLAGS=-Werror pg_travis_multi_test check
 after_success:

src/test/regress/pg_regress_multi.pl

@@ -467,7 +467,8 @@ if ($vanillatest)
     $ENV{PGPORT} = $masterPort;
     $ENV{PGUSER} = $user;
 
-    system("make -C $postgresBuilddir/src/test/regress installcheck-parallel")
+    system("make -C $postgresBuilddir/src/test/regress installcheck-parallel") == 0
+    or die "Could not run vanilla tests";
 }
 elsif ($isolationtester)
 {