chore(Makefile): fix coverage-report target (#898)

* update Makefile

* add coverage html to gitignire

.gitignore

@@ -10,6 +10,7 @@
 coverage
 coverage.json
 coverage.out
+coverage.html
 node_modules
 release/
 typechain

Makefile

@@ -26,7 +26,7 @@ TEST_DIR?="./..."
 TEST_BUILD_FLAGS := -tags TESTNET,pebbledb,ledger
 PRIV_BUILD_FLAGS := -tags PRIVNET,pebbledb,ledger
 
-clean: clean-binaries clean-dir clean-test-dir
+clean: clean-binaries clean-dir clean-test-dir clean-coverage
 
 clean-binaries:
 	@rm -rf ${GOBIN}/zetacored
@@ -39,13 +39,18 @@ clean-dir:
 all: install
 
 test-coverage-exclude-core:
-	@go test {TEST_BUILD_FLAGS} -v -coverprofile coverage.out $(go list ./... | grep -v /x/zetacore/)
+	@go test ${TEST_BUILD_FLAGS} -v -coverprofile coverage.out $(go list ./... | grep -v /x/zetacore/)
 
 test-coverage:
-	@go test ${TEST_BUILD_FLAGS} -v -coverprofile coverage.out ${TEST_DIR}
+	-@go test ${TEST_BUILD_FLAGS} -v -coverprofile coverage.out ${TEST_DIR}
 
 coverage-report: test-coverage
-	@go tool cover -html=cover.txt
+	@go tool cover -html=coverage.out -o coverage.html
+
+clean-coverage:
+	@rm -f coverage.out
+	@rm -f coverage.html
+
 clean-test-dir:
 	@rm -rf x/crosschain/client/integrationtests/.zetacored
 	@rm -rf x/crosschain/client/querytests/.zetacored