Refactor parts of the code and add more tests

This is a refactor of parts of the code, some minor things such as adding
punctuation in the end of sentences and making the code a bit easier to read.

More tests has been added in the form of gometalinter which checks the code
health, style and spelling errors. The flaky cleanup test should also be fixed
with this commit.

Makefile

@@ -1,13 +1,39 @@
 all: get-deps build
 
+.PHONY: build
 build:
-	@go build pgstore.go
+	go build ./...
 
+.PHONY: get-deps
 get-deps:
-	@go get -d -v ./...
+	go get -v ./...
 
-test: get-deps
-	@go test -v ./...
+.PHONY: test
+test: get-deps metalint check
 
-format:
-	@go fmt ./...
+.PHONY: check
+check:
+	go test -v -race -cover ./...
+
+.PHONY: metalint
+metalint:
+	which gometalinter > /dev/null || (go get github.com/alecthomas/gometalinter && gometalinter --install --update)
+	gometalinter --cyclo-over=20 -e "struct field Id should be ID" --enable="gofmt -s" --enable=misspell --fast ./...
+
+.PHONY: fmt
+fmt:
+	@go fmt ./... | awk '{ print "Please run go fmt"; exit 1 }'
+
+.PHONY: docker-test
+docker-test:
+	docker run -d -p 5432:5432 --name=pgstore_test_1 postgres:9.4
+	sleep 5
+	docker run --rm --link pgstore_test_1:postgres postgres:9.4 psql -c 'create database test;' -U postgres -h postgres
+	PGSTORE_TEST_CONN="postgres://postgres@127.0.0.1:5432/test?sslmode=disable" make check
+	docker kill pgstore_test_1
+	docker rm pgstore_test_1
+
+.PHONY: docker-clean
+docker-clean:
+	-docker kill pgstore_test_1
+	-docker rm pgstore_test_1