Include tests using MANIFEST.in instead of setup.py

Fixes #28, #90. This should result in tests being included in the source
distribution (along with docs for package maintainers to use); but not
being "installed" when the module is installed (as users complain the
tests aren't needed at runtime).

#28
#63
#90

MANIFEST.in

@@ -1,4 +1,5 @@
-include README.md
+global-exclude *.py[co]
+include colorlog/tests/
+include doc/
 include LICENSE
-include colorlog/tests/test_config.ini
-graft doc
+include README.md

setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name='colorlog',
-    version='4.4.0',
+    version='4.5.0',
 
     description='Log formatting with colors!',
     long_description=open('README.md').read(),
@@ -14,8 +14,7 @@
     license='MIT License',
 
     packages=[
-        'colorlog',
-        'colorlog.tests'
+        'colorlog'
     ],
 
     setup_requires=[