Merge pull request #15 from jnsebgosselin/move_install_require

PR: Move install requires to extras requires

README.md

@@ -20,3 +20,15 @@ You can update `QtAppUtils` by running:
 ```commandlines
 pip install qtapputils -U
 ```
+
+This will only install or update `qtapputils` without installing of updating
+the dependencies.
+
+The above commands will only install or update `QtAppUtils` without
+its dependencies.
+
+To install `QtAppUtils` along with its dependencies, you can use:
+
+```commandlines
+pip install qtapputils[with-deps]
+```

setup.py

@@ -38,7 +38,7 @@
       packages=setuptools.find_packages(),
       package_data={},
       include_package_data=True,
-      install_requires=INSTALL_REQUIRES,
+      extras_require={'with-deps': INSTALL_REQUIRES},
       classifiers=["Programming Language :: Python :: 3",
                    "License :: OSI Approved :: MIT License",
                    "Operating System :: OS Independent"],