Remove flanker and replace PyML with scikit-learn

I never was actually able to successfully install PyML but the source-forge
distribution and lack of python3 support convinced me that scikit-learn would
be a fine substitute. Flanker was also difficult for me to install and seemed
only to be used in the tests, so I removed it as well to get into a position
where I could run the tests. As of this commit, only one is not passing
(test_standard_replies with android.eml) though I'm not familiar with the `email`
library yet.

setup.py

@@ -1,8 +1,3 @@
-import os
-import sys
-import contextlib
-
-from distutils.spawn import find_executable
 from setuptools import setup, find_packages
 
 
@@ -20,87 +15,11 @@ setup(name='talon',
       zip_safe=True,
       install_requires=[
           "lxml==2.3.3",
-          "regex==0.1.20110315",
-          "chardet==1.0.1",
-          "dnspython==1.11.1",
+          "regex==0.1.20110315",  # handling of .* changes from version 0 to 1
           "html2text",
           "nose==1.2.1",
           "mock",
           "coverage",
-          "flanker"
+          "scikit-learn",
           ]
       )
-
-
-def install_pyml():
-    '''
-    Downloads and installs PyML
-    '''
-    try:
-        import PyML
-    except:
-        pass
-    else:
-        return
-
-    # install numpy first
-    pip('install numpy==1.6.1 --upgrade')
-
-    pyml_tarball = (
-        'http://09cce49df173f6f6e61f-fd6930021b51685920a6fa76529ee321'
-        '.r45.cf2.rackcdn.com/PyML-0.7.9.tar.gz')
-    pyml_srcidr = 'PyML-0.7.9'
-
-    # see if PyML tarball needs to be fetched:
-    if not dir_exists(pyml_srcidr):
-        run("curl %s | tar -xz" % pyml_tarball)
-
-    # compile&install:
-    with cd(pyml_srcidr):
-        python('setup.py build')
-        python('setup.py install')
-
-
-def run(command):
-    if os.system(command) != 0:
-        raise Exception("Failed '{}'".format(command))
-    else:
-        return 0
-
-
-def python(command):
-    command = '{} {}'.format(sys.executable, command)
-    run(command)
-
-
-def enforce_executable(name, install_info):
-    if os.system("which {}".format(name)) != 0:
-        raise Exception(
-            '{} utility is missing.\nTo install, run:\n\n{}\n'.format(
-                name, install_info))
-
-
-def pip(command):
-    command = '{} {}'.format(find_executable('pip'), command)
-    run(command)
-
-
-def dir_exists(path):
-    return os.path.isdir(path)
-
-
-@contextlib.contextmanager
-def cd(directory):
-    curdir = os.getcwd()
-    try:
-        os.chdir(directory)
-        yield {}
-    finally:
-        os.chdir(curdir)
-
-
-if __name__ == '__main__':
-    if len(sys.argv) > 1 and sys.argv[1] in ['develop', 'install']:
-        enforce_executable('curl', 'sudo aptitude install curl')
-
-        install_pyml()