WIP: Add support for testing upgrade scripts (yugabyte#128)

Add support for testing of pgTap update scripts.

This commit adds several new make targets:

- make uninstall-all: remove ALL installed pgtap code. Unlike `make unintall`, this removes pgtap*, not just our defined targets. Useful when testing multiple versions of pgtap.
- make regress: run installcheck then print any diffs from expected output.
- make updatecheck: install an older version of pgTap from PGXN (controlled by $UPDATE_FROM; 0.95.0 by default), update to the current version via ALTER EXTENSION, then run installcheck.
- make results: runs `make test` and copies all result files to test/expected/. DO NOT RUN THIS UNLESS YOU'RE CERTAIN ALL YOUR TESTS ARE PASSING!

In addition to these changes, `make installcheck` now runs as many tests as possible in parallel. This is much faster than running them sequentially. The degree of parallelism can be controlled via `$PARALLEL_CONN`. Setting `$PARALLEL_CONN` to `1` will go back to a serial test schedule.

.gitignore

@@ -1,16 +1,18 @@
+# THERE IS ANOTHER .gitignore IN test/sql!
+
 .*.swp
 pgtap.sql
 pgtap-core.sql
 pgtap-schema.sql
 uninstall_pgtap.sql
-test/setup.sql
 results
 pgtap.so
 regression.*
 *.html
 *.html1
 *.sql.orig
 bbin
+
 /sql/pgtap--?.??.?.sql
 /sql/pgtap--?.?.?.sql
 /sql/pgtap-core--*
@@ -21,6 +23,10 @@ bbin
 /sql/pgtap--0.98.0--0.99.0.sql
 /sql/pgtap--0.99.0--1.0.0.sql
 /sql/pgtap-static.sql
+/sql/pgtap-static.sql.tmp*
+*.sql.orig
+
+test/build
 
 # Misc mac crap
 .DS_Store

.travis.yml

@@ -1,18 +1,27 @@
 language: c
 before_install:
   - wget https://gist.githubusercontent.com/petere/5893799/raw/apt.postgresql.org.sh
-  - wget https://gist.githubusercontent.com/petere/6023944/raw/pg-travis-test.sh
   - sudo sh ./apt.postgresql.org.sh
   - sudo rm -vf /etc/apt/sources.list.d/pgdg-source.list
+script:
+  - bash ./pg-travis-test.sh
+
 env:
-  - PGVERSION=8.4
-  - PGVERSION=9.0
   - PGVERSION=9.1
   - PGVERSION=9.2
   - PGVERSION=9.3
   - PGVERSION=9.4
   - PGVERSION=9.5
   - PGVERSION=9.6
   - PGVERSION=10
-  - PGVERSION=11
+  - PGVERSION=11 UPDATE_FROM=0.99.0
+  # Duplication below is via s/-/- PARALLEL_CONN=1/
+  - PARALLEL_CONN=1 PGVERSION=9.1
+  - PARALLEL_CONN=1 PGVERSION=9.2
+  - PARALLEL_CONN=1 PGVERSION=9.3
+  - PARALLEL_CONN=1 PGVERSION=9.4
+  - PARALLEL_CONN=1 PGVERSION=9.5
+  - PARALLEL_CONN=1 PGVERSION=9.6
+  - PARALLEL_CONN=1 PGVERSION=10
+  - PARALLEL_CONN=1 PGVERSION=11 UPDATE_FROM=0.99.0
 script: bash ./pg-travis-test.sh