Properly documented the dependency on wcwidth

tableformatter depends on wcwidth for all OSes, not use POSIX OSes.
- setup.py and README.md have been updated accordingly
- was also able to remove wcwidth from tox.ini since it is a full-blown dependency now

Author: tleonhardt

README.md

@@ -25,9 +25,10 @@ pip install tableformatter
 
 Dependencies
 ------------
-``tableformatter`` does not have any required dependencies.
+``tableformatter`` depends on the [wcwidth](https://github.com/jquast/wcwidth) module for measuring the width of 
+unicode strings rendered to a terminal.
 
-However, if you wish to use the provided optional support for color, then at least one of the following two modules must be installed:
+If you wish to use the optional support for color, then at least one of the following two modules must be installed:
 * [colorama](https://github.com/tartley/colorama)
 * [colored](https://github.com/dslackw/colored)
 

setup.py

@@ -30,10 +30,10 @@
 Topic :: Software Development :: Libraries :: Python Modules
 """.splitlines())))
 
+INSTALL_REQUIRES = ['wcwidth']
+
 EXTRAS_REQUIRE = {
-    # POSIX OSes also require wcwidth for correctly estimating the displayed width of unicode chars
-    ":sys_platform!='win32'": ['wcwidth'],
-    # Python 3.4 and earlier the typing module backport for optional type hinting support
+    # Python 3.4 and earlier require the typing module backport for type hinting support
     ":python_version<'3.5'": ['typing'],
     # development only dependencies - install with 'pip install -e .[dev]'
     'dev': [
@@ -56,5 +56,6 @@
     py_modules = ['tableformatter'],
     keywords='table tabular formatter',
     python_requires='>=3.4',
+    install_requires=INSTALL_REQUIRES,
     extras_require=EXTRAS_REQUIRE,
 )

tox.ini

@@ -15,7 +15,6 @@ deps =
   pytest
   pytest-cov
   pytest-mock
-  wcwidth
 commands =
   py.test {posargs} --cov
   codecov
@@ -25,7 +24,6 @@ deps =
   mock
   pytest
   pytest-mock
-  wcwidth
 commands = py.test -v
 
 [testenv:py35-win]
@@ -40,7 +38,6 @@ deps =
   pytest
   pytest-cov
   pytest-mock
-  wcwidth
 commands =
   py.test {posargs} --cov
   codecov
@@ -58,6 +55,5 @@ commands =
 deps =
   pytest
   pytest-mock
-  wcwidth
 commands = py.test -v