Adds a Makefile to facilitate common development tasks

When working on #219, I found it repetitive to use history to invoke
commands when I could just type "make" like I do in many other projects,
including my Python projects. I extracted therefrom this minimalistic
Makefile and added references to it in CONTRIBUTING. I also cleaned up
some markup in CONTRIBUTING.

CONTRIBUTING.md

@@ -1,19 +1,19 @@
 # Contributing
 
-We always like contributions here in ``peru``! 
+We always like contributions here in `peru`!
 
 First of all, if you're looking for something to work or you have some idea for a new feature or you found a bug, then check out our [issue tracker](https://github.com/buildinspace/peru/issues) for this.
 
 In the issue, discuss your idea and implementation.
 
-Then if you want to make a contribution to ``peru`` then please raise a
+Then if you want to make a contribution to `peru` then please raise a
 [Pull Request](https://github.com/buildinspace/peru/pulls) on GitHub.
 
 To help speed up the review process please ensure the following:
 
 - The PR addresses an open issue.
-- The project passes linting with ``flake8 peru tests``.
-- All tests are passing locally with (includes linting): ``python test.py``.
+- The project passes linting with `make check` or `flake8 peru tests`.
+- All tests are passing locally with (includes linting): `make test` or `python test.py`.
 - If adding a new feature you also add documentation.
 
 ## Developing
@@ -24,48 +24,67 @@ To check out a local copy of the project you can [fork the project on GitHub](ht
 and then clone it locally. If you are using https, then you should adapt to it.
 
 ```bash
-   $ git clone [email protected]:yourusername/peru.git
-   $ cd peru
+git clone [email protected]:yourusername/peru.git
+cd peru
 ```
 
-This project uses ``flake8`` for linting.  To configure your local environment please install these development dependencies.
+This project uses `flake8` for linting. To configure your local environment, please install these development dependencies.
+You may want to do this in a virtualenv; use `make venv` to create it in
+`.venv` in the current directory.
 
 ```bash
-   $ pip install requirements-dev.txt
+make deps-dev
+# OR
+pip install -r requirements-dev.txt
+```
+
+then you can run `flake8` with
+
+```bash
+make check
+# OR
+flake8 peru tests
 ```
 
 ## Testing
 
 You can check that things are working correctly by calling the tests.
 
 ```bash
-    $ python test.py -v
-    test_safe_communicate (test_async.AsyncTest) ... ok
-    test_basic_export (test_cache.CacheTest) ... ok
-    .
-    .
-    .
-    test_assert_contents (test_test_shared.SharedTestCodeTest) ... ok
-    test_create_dir (test_test_shared.SharedTestCodeTest) ... ok
-    test_read_dir (test_test_shared.SharedTestCodeTest) ... ok
+make test
+# OR
+python test.py -v
+```
+
+```
+$ python test.py -v
+test_safe_communicate (test_async.AsyncTest) ... ok
+test_basic_export (test_cache.CacheTest) ... ok
+.
+.
+.
+test_assert_contents (test_test_shared.SharedTestCodeTest) ... ok
+test_create_dir (test_test_shared.SharedTestCodeTest) ... ok
+test_read_dir (test_test_shared.SharedTestCodeTest) ... ok
 ----------------------------------------------------------------------
 Ran 152 tests in 45.11s
 
 OK (skipped=1)
-````
+```
+
 These checks will be run automatically when you make a pull request.
 
 You should always have a skipped test, because this is a platform specific tests.
 
 If you are working on a new feature please add tests to ensure the feature works as expected. If you are working on a bug fix then please add a test to ensure there is no regression.
 
-Tests are stored in ``peru/tests`` and verify the current implementation to see how your test will fit in.
+Tests are stored in `peru/tests` and verify the current implementation to see how your test will fit in.
 
 ## Making a Pull Request
 
 Once you have made your changes and are ready to make a Pull Request please ensure tests and linting pass locally before pushing to GitHub.
 
-When making your Pull Request please include a short description of the changes, but more importantly why they are important. 
+When making your Pull Request please include a short description of the changes, but more importantly why they are important.
 
 Perhaps by writing a before and after paragraph with user examples.
 
@@ -80,7 +99,7 @@ This PR includes a new feature that ...
 
 **Before**
 
-If a user tried to pull a repository ... 
+If a user tried to pull a repository ...
 
     ```python
         > code example
@@ -96,4 +115,4 @@ If a user tries to pull a repository now ...
     ```
 ```
 
-After that you should wait the review and perform possible changes in the submitted code.
+After that you should wait the review and perform possible changes in the submitted code.

Makefile

@@ -0,0 +1,35 @@
+PYTHON ?= python3
+FLAKE8 ?= flake8
+PIP ?= pip3
+
+VENV ?= .venv
+
+##@ Code Quality
+
+.PHONY: all
+all: check test ## Run all checks and tests
+
+.PHONY: test
+test: ## Run all tests
+	$(PYTHON) test.py -v
+
+.PHONY: check
+check: ## Run all checks
+	$(FLAKE8) peru tests
+
+##@ Dev Env Setup
+
+.PHONY: venv
+venv: ## Create a venv
+	$(PYTHON) -m venv --clear $(VENV)
+	@echo "Activate the venv with 'source $(VENV)/bin/activate'"
+
+.PHONY: deps-dev
+deps-dev: ## Install development dependencies
+	$(PIP) install -r requirements-dev.txt
+
+##@ Utility
+
+.PHONY: help
+help:  ## Display this help
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m\033[0m\n"} /^[\#a-zA-Z0-9_-]+:.*?##/ { printf "  \033[36m%-15s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)