docs: improvement on dev setup on contributing (#676)

Improvement on `How to contribute` section informing required tools and
how to build, test and coverage. This commit also add a new make command
to easily build on development.

Signed-off-by: Matheus Alcantara <matheus.alcantara@zup.com.br>

CONTRIBUTING.md

@@ -12,7 +12,7 @@ This is Horusec contributing guide. Please read the following sections to learn
    2. [**Code Review**](#Code-Review)
    3. [**Pull Requests**](#Pull-Requests)    
 3. [**How to contribute?**](#How-to-contribute?)
-      1. [**Prepare your development environment**](#Using-Docker)
+      1. [**Prepare your development environment**](#Prepare-your-development-environment)
       2. [**First contribution**](#First-contribution)
       4. [**Add new feature, bugfixing or improvement**](#Add-new-feature-bugfixing-or-improvement)
       5. [**Pull Request's approval**](#Pull-Request's-approval)
@@ -74,6 +74,34 @@ When opening a PR:
 See the guidelines to submit your changes: 
 
 ### **Prepare your development environment**
+To start contributing with Horusec you first need to install [Go](https://golang.org/dl/). The minimal version required to build is 1.17.
+[GNU Make](https://www.gnu.org/software/make/) is also required to development.
+
+After installing Go you can build using `make build-dev`.
+
+
+#### Testing
+Horusec has a suite of unit and end-to-end tests you can run them using the following commands. 
+
+```
+make test
+
+make test-e2e
+```
+
+Make sure all the tests pass before you commit and push :)
+
+#### Coverage
+You can get the test coverage using the following command.
+
+```bash
+make coverage
+
+go tool cover -html=coverage.out # Open coverage status in your browser
+``` 
+
+---
+
 Horusec has other repositories and you can check the README for each one of them: 
 
 - [**Admin**](https://github.com/ZupIT/horusec-admin)
@@ -127,4 +155,4 @@ Your pull request is approved when:
 
 Thank you for your contribution, you rock! 🚀
 
-**Horusec team** 
+**Horusec team** 

Makefile

@@ -9,6 +9,7 @@ ADDLICENSE ?= addlicense
 HORUSEC ?= horusec
 DOCKER_COMPOSE ?= docker-compose
 PATH_BINARY_BUILD_CLI ?= $(GOPATH)/bin
+MAIN = ./cmd/app
 
 fmt:
 	$(GOFMT) -w $(GO_FILES)
@@ -58,37 +59,40 @@ security:
 		$(HORUSEC) start -p="./" -e="true"
     endif
 
+build-dev:
+	$(GO) build -o horusec $(MAIN)
+
 build-install-cli-linux:
 	rm -rf "$(PATH_BINARY_BUILD_CLI)/horusec-linux" &> /dev/null
-	CGO_ENABLED=0 GOOS=linux $(GO) build -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-linux" ./cmd/app/main.go
+	CGO_ENABLED=0 GOOS=linux $(GO) build -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-linux" $(MAIN)
 	chmod +x "$(PATH_BINARY_BUILD_CLI)/horusec-linux"
 	horusec-linux version
 
 build-install-cli-darwin:
 	rm -rf "$(PATH_BINARY_BUILD_CLI)/horusec-mac" &> /dev/null
-	CGO_ENABLED=0 GOOS=darwin $(GO) build -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-mac" ./cmd/app/main.go
+	CGO_ENABLED=0 GOOS=darwin $(GO) build -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-mac" $(MAIN)
 	chmod +x "$(PATH_BINARY_BUILD_CLI)/horusec-mac"
 	horusec-mac version
 
 build-install-cli-windows:
 	rm -rf "$(PATH_BINARY_BUILD_CLI)/horusec-win.exe" &> /dev/null
-	env GOOS=windows GOARCH=amd64 $(GO) build -o "$(PATH_BINARY_BUILD_CLI)/horusec-win.exe" ./cmd/app/main.go
+	env GOOS=windows GOARCH=amd64 $(GO) build -o "$(PATH_BINARY_BUILD_CLI)/horusec-win.exe" $(MAIN)
 
 build-install-stand-alone-cli-linux:
 	rm -rf "$(PATH_BINARY_BUILD_CLI)/horusec-linux" &> /dev/null
-	CGO_ENABLED=0 GOOS=linux $(GO) build -ldflags "-X github.com/ZupIT/horusec/config/dist.standAlone=true" -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-linux" ./cmd/app/main.go
+	CGO_ENABLED=0 GOOS=linux $(GO) build -ldflags "-X github.com/ZupIT/horusec/config/dist.standAlone=true" -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-linux" $(MAIN)
 	chmod +x "$(PATH_BINARY_BUILD_CLI)/horusec-linux"
 	horusec-linux version
 
 build-install-stand-alone-cli-darwin:
 	rm -rf "$(PATH_BINARY_BUILD_CLI)/horusec-mac" &> /dev/null
-	CGO_ENABLED=0 GOOS=darwin $(GO) build -ldflags "-X github.com/ZupIT/horusec/config/dist.standAlone=true" -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-mac" ./cmd/app/main.go
+	CGO_ENABLED=0 GOOS=darwin $(GO) build -ldflags "-X github.com/ZupIT/horusec/config/dist.standAlone=true" -a -installsuffix cgo -o "$(PATH_BINARY_BUILD_CLI)/horusec-mac" $(MAIN)
 	chmod +x "$(PATH_BINARY_BUILD_CLI)/horusec-mac"
 	horusec-mac version
 
 build-install-stand-alone-cli-windows:
 	rm -rf "$(PATH_BINARY_BUILD_CLI)/horusec-win.exe" &> /dev/null
-	env GOOS=windows GOARCH=amd64 $(GO) build -ldflags "-X github.com/ZupIT/horusec/config/dist.standAlone=true" -o "$(PATH_BINARY_BUILD_CLI)/horusec-win.exe" ./cmd/app/main.go
+	env GOOS=windows GOARCH=amd64 $(GO) build -ldflags "-X github.com/ZupIT/horusec/config/dist.standAlone=true" -o "$(PATH_BINARY_BUILD_CLI)/horusec-win.exe" $(MAIN)
 
 install:
 	./deployments/scripts/install.sh latest