Updated Readme with pipenv info

Author: avara1986

README.md

@@ -35,3 +35,49 @@ Encapsulate common rest operations between business services propagating trace h
 
 ### pyms/tracer
 Create an injector `flask_opentracing.FlaskTracer` to use in our projects
+
+## Pipenv
+
+### Advantages over plain pip and requirements.txt
+[Pipenv](https://pipenv.readthedocs.io/en/latest/) generates two files: a `Pipfile`and a `Pipfile.lock`.
+* `Pipfile`: Is a high level declaration of the dependencies of your project. It can contain "dev" dependencies (usually test related stuff) and "standard" dependencies which are the ones you'll need for your project to function
+* `Pipfile.lock`: Is the "list" of all the dependencies your Pipfile has installed, along with their version and their hashes. This prevents two things: Conflicts between dependencies and installing a malicious module.
+
+### How to...
+
+Here the most 'common' `pipenv` commands, for a more in-depth explanation please refer to  the [official documentation](https://pipenv.readthedocs.io/en/latest/).
+
+#### Install pipenv
+```bash
+pip install pipenv
+```
+
+#### Install dependencies defined in a Pipfile
+```bash
+pipenv install
+```
+
+#### Install both dev and "standard" dependencies defined in a Pipfile
+```bash
+pipenv install --dev
+```
+
+#### Install a new module
+```bash
+pipenv install django
+```
+
+#### Install a new dev module (usually test related stuff)
+```bash
+pipenv install nose --dev
+```
+
+#### Install dependencies in production
+```bash
+pipenv install --deploy
+```
+
+#### Start a shell
+```bash
+pipenv shell
+```