Apply upstream's PR #250 to "development" branch

.travis.yml

@@ -11,6 +11,7 @@ before_install:
   # Define TZ as some tests rely on timezone
   - export TZ=Europe/Brussels
   - pip install --quiet pytest==4.4 pytest-cov pytest-xdist chardet
+  - pip install ".[mysql]"
 
 install:
   - python setup.py install --quiet

README.md

@@ -57,6 +57,12 @@ If you have pip, you can automatically download and install from the [PyPI repos
 pip install pattern
 ```
 
+If you wish to use MySQL support, install specifying the optional extra
+requirement:
+```
+pip install pattern[mysql]
+```
+
 If none of the above works, you can make Python aware of the module in three ways:
 - Put the pattern folder in the same folder as your script.
 - Put the pattern folder in the standard location for modules so it is available to all scripts:

setup.py

@@ -137,7 +137,6 @@
     install_requires = [
         "future",
         "backports.csv",
-        "mysqlclient",
         "beautifulsoup4",
         "lxml",
         "feedparser",
@@ -149,5 +148,8 @@
         "cherrypy" if sys.version >= "3" else "cherrypy==17.4.1",
         "requests"
     ],
+    extras_require = {
+        'mysql': ["mysqlclient"],
+    },
     zip_safe = False
 )