Nixify CircleCI setup (#1535)

* package ghr
* add nix-based release scripts
* refactor CI based on nix tests and release scripts
* update stack version in circleci
* update makefile
* remove docker directory
* add Docker Hub description
* add README on docker

Makefile

@@ -1,4 +1,4 @@
-.PHONY: commit-check check clean lint style test test-watch coverage circleci circleci-prof-test check-dburi prompt-clean prompt-long-process
+.PHONY: commit-check check clean lint style test test-watch coverage circleci circleci-memory prompt-clean prompt-long-process cachix-push-all
 
 commit-check: lint style
 
@@ -10,32 +10,34 @@ clean: prompt-clean
 # For running these you'll need to install hlint and stylish-haskell first. Run:
 # stack install hlint stylish-haskell
 lint:
-	git ls-files | grep '\.l\?hs$$' | xargs stack exec -- hlint -X QuasiQuotes -X NoPatternSynonyms "$$@"
+	git ls-files | grep '\.l\?hs$$' | \
+	  xargs stack exec -- hlint -X QuasiQuotes -X NoPatternSynonyms "$$@"
 
 style:
-	git ls-files | grep '\.l\?hs$$' | xargs stack exec -- stylish-haskell -i && git diff-index --exit-code HEAD -- '*.hs' '*.lhs'
+	git ls-files | grep '\.l\?hs$$' | xargs stack exec -- stylish-haskell -i
 
-test: check-dburi
-	stack test
+test:
+	test/with_tmp_db stack test
 
-test-watch: check-dburi
-	stack build --file-watch --test --test-arguments '--rerun --failure-report=.TESTREPORT --rerun-all-on-success'
+test-watch:
+	test/with_tmp_db stack build --file-watch --test \
+	  --test-arguments '--rerun --failure-report=.TESTREPORT --rerun-all-on-success'
 
-coverage: check-dburi clean
+coverage: clean
 	stack build --coverage
-	stack test --coverage
+	test/with_tmp_db stack test --coverage
 
 circleci: prompt-long-process
-	circleci local execute --job build-test-9.4
+	circleci local execute --job stack-test
 
-circleci-prof-test: prompt-long-process
-	circleci local execute --job build-prof-test
-
-check-dburi:
-	test -n "$(POSTGREST_TEST_CONNECTION)" # Requires POSTGREST_TEST_CONNECTION environmental variable
+circleci-memory: prompt-long-process
+	circleci local execute --job stack-test-memory
 
 prompt-clean:
 	@echo -n 'Are you sure? You will have to rebuild. [y/N] ' && read ans && [ $${ans:-N} = y ]
 
 prompt-long-process:
 	@echo -n 'Are you sure? This might take a while. [y/N] ' && read ans && [ $${ans:-N} = y ]
+
+cachix-push-all:
+	nix-store -qR --include-outputs $$(nix-instantiate) | cachix push postgrest