MDLSITE-4211 add travisfile and tests structure

There are actually quit a few things i'm not a fan of from my first
playing with bats - one was the fact there isn't a good way to get
output from failed tests! So because of that I have also included the
bats-assert and bats-error libraries.

See https://github.com/ztombol/bats-docs for details of the assertion
lib.

.travis.yml

@@ -0,0 +1,15 @@
+language: php
+php:
+    - '7.0'
+sudo: false
+cache:
+  directories:
+      - $HOME/cachedir
+install: git clone --depth 1 https://github.com/sstephenson/bats.git $HOME/bats
+before_script:
+  - 'git config --global user.email "travis@localhost" && git config --global user.name "Travis CI"'
+  - "export LOCAL_CI_TESTS_CACHEDIR=$HOME/cachedir && mkdir -p $LOCAL_CI_TESTS_CACHEDIR"
+  - "export LOCAL_CI_TESTS_GITDIR=$HOME/gitdir && git clone git://github.com/moodle/moodle $LOCAL_CI_TESTS_GITDIR"
+script:
+  - $HOME/bats/bin/bats tests
+

tests/01-setup.bats

@@ -0,0 +1,9 @@
+#!/usr/bin/env bats
+
+load libs/shared_setup
+
+# This test is just used as some quick output because some tests are v.slow
+@test "Git is setup for tests." {
+    [ -d "$gitdir/.git" ];
+    assert_success
+}

tests/libs/bats-assert/load.bash

@@ -0,0 +1 @@
+source "$(dirname "${BASH_SOURCE[0]}")/src/assert.bash"