Align with master and fix dependencies (#561)

Author: Mec-iS

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,14 +1,18 @@
-<!-- Please create/claim an issue before sending a PR -->
+<!-- Please create (if there is not one yet) a issue before sending a PR -->
 <!-- Add issue number (Eg: fixes #123) -->
+<!-- Always provide changes in existing tests or new tests -->
 
 Fixes #
 
 ### Checklist
 - [ ] My branch is up-to-date with upstream/develop branch.
 - [ ] Everything works and tested for Python 3.6.0 and above.
 
-### Description
-<!-- Describe about what this PR does, previous state and new state of the output -->
+### Current behaviour
+<!-- Describe the code you are going to change and its behaviour -->
+
+### New expected behaviour
+<!-- Describe the new code and its expected behaviour -->
 
 ### Change logs
 

README.md

@@ -63,15 +63,30 @@ cd hydrus
 git checkout -b develop origin/develop
 ```
 
+Install a [*Python virtual environment*](https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/) using:
+```bash
+python3.7 -m venv .venv
+```
+or:
+```bash
+virtualenv -p python3.7 .venv
+```
+
 Install hydrus using:
 ```bash
-pip3 install -r requirements.txt
+source .venv/bin/activate
+pip install -r requirements.txt
+python setup.py install
+```
 
-python3 setup.py install
+NOTE: there is an alternative way to install dependencies with `poetry`:
+```bash
+pip3 install poetry
+poetry install
 ```
+This is mostly used to check dependencies conflicts among packages.
 
-and run the server using:
-
+After installation is successful, to run the server:
 ```bash
 hydrus serve
 ```