tests: switch to bats-core

This switches from the older, unmaintained version of bats to one that _is_ maintained. In particular, this fork of the community version - bats-core/bats-core - adds junit timing support, which can be used to track down slow tests.

Once the bats-core/bats-core repository merges junit support, we will switch back to upstream.

Note that tests on OS X will still run using a version that _does not_ have junit timing support.

tests.mk

@@ -58,15 +58,15 @@ ifeq ($(shell grep dokku.me /home/dokku/VHOST 2>/dev/null),)
 endif
 
 bats:
-ifneq ($(shell bats --version > /dev/null 2>&1 ; echo $$?),0)
 ifeq ($(SYSTEM),Darwin)
-	brew install bats
+ifneq ($(shell bats --version > /dev/null 2>&1 ; echo $$?),0)
+	brew install bats-core
+endif
 else
-	git clone https://github.com/sstephenson/bats.git /tmp/bats
+	git clone https://github.com/josegonzalez/bats-core.git /tmp/bats
 	cd /tmp/bats && sudo ./install.sh /usr/local
 	rm -rf /tmp/bats
 endif
-endif
 
 lint:
 	# these are disabled due to their expansive existence in the codebase. we should clean it up though