pyproject.toml: add optional dependencies

[dulmandakh]

This PR adds support for installing with optional dependencies. Fixes #684

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.44%. Comparing base (f00421d) to head (56ac5da).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #763      +/-   ##
==========================================
- Coverage   73.79%   70.44%   -3.36%     
==========================================
  Files          26       26              
  Lines        1675     1678       +3     
==========================================
- Hits         1236     1182      -54     
- Misses        439      496      +57     

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[claudep]

Looks good, however I think this deserves a note somewhere in the documentation, probably in installation.rst.

[dulmandakh]

Looks good, however I think this deserves a note somewhere in the documentation, probably in installation.rst.

I tried to write some, but couldn't finish due to my language skills.

[dulmandakh]

@claudep could you please help with the documentation

[claudep]

I did not forget you and will return to this as soon as time permits, thanks for your patience!

[claudep]

I suggest installing this patch:

diff --git a/docs/installation.rst b/docs/installation.rst
index 9402faa..4f87538 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -5,11 +5,15 @@ Installation & Setup
 Installation
 ============
 First you need to make sure to read the :doc:`requirements`. To install
-sorl-thumbnail is easy::
+sorl-thumbnail::
 
     pip install sorl-thumbnail
 
-Or you can go to `the github page <https://github.com/sorl/sorl-thumbnail>`_
+Depending of the chosen image backend, you may also use one of::
+
+    pip install sorl-thumbnail[pil]
+    pip install sorl-thumbnail[wand]
+    pip install sorl-thumbnail[pgmagick]
 
 Setup
 =====

[dulmandakh]

I suggest installing this patch:

diff --git a/docs/installation.rst b/docs/installation.rst
index 9402faa..4f87538 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -5,11 +5,15 @@ Installation & Setup
 Installation
 ============
 First you need to make sure to read the :doc:`requirements`. To install
-sorl-thumbnail is easy::
+sorl-thumbnail::
 
     pip install sorl-thumbnail
 
-Or you can go to `the github page <https://github.com/sorl/sorl-thumbnail>`_
+Depending of the chosen image backend, you may also use one of::
+
+    pip install sorl-thumbnail[pil]
+    pip install sorl-thumbnail[wand]
+    pip install sorl-thumbnail[pgmagick]
 
 Setup
 =====

done, thank you

[dulmandakh]

@claudep added documentation changes per your suggestion. thank you

[claudep]

Thanks great! I have still one question. Shouldn't we name the optional dependency imgmagick or imagemagick instead of wand? Of course, behind the scene, we're still installing the wand lib.

[dulmandakh]

IIRC, there is another backend for imagemagick.

[claudep]

Ah yes, you're right.

[claudep]

👍