refactor and simplify configuration loading

tests/fixtures/config_files/README.rst

@@ -16,17 +16,7 @@ Files that should not be created
 Purposes of existing fixtures
 -----------------------------
 
-``tests/fixtures/config_files/cli-specified.ini``
-
-    This should only be used when providing config file(s) specified by the
-    user on the command-line.
-
 ``tests/fixtures/config_files/local-plugin.ini``
 
     This is for testing configuring a plugin via flake8 config file instead of
     setuptools entry-point.
-
-``tests/fixtures/config_files/no-flake8-section.ini``
-
-    This should be used when parsing an ini file without a ``[flake8]``
-    section.

tests/fixtures/config_files/broken.ini

@@ -1,9 +0,0 @@
-[flake8]
-exclude =
-<<<<<<< 642f88cb1b6027e184d9a662b255f7fea4d9eacc
-    tests/fixtures/,
-=======
-    tests/,
->>>>>>> HEAD
-    docs/
-ignore = D203

tests/fixtures/config_files/cli-specified-with-inline-comments.ini

@@ -1,16 +0,0 @@
-[flake8]
-# This is a flake8 config, there are many like it, but this is mine
-ignore =
-    # Disable E123
-    E123,
-    # Disable W234
-    W234,
-    # Also disable E111
-    E111
-exclude =
-    # Exclude foo/
-    foo/,
-    # Exclude bar/ while we're at it
-    bar/,
-    # Exclude bogus/
-    bogus/

tests/fixtures/config_files/cli-specified-without-inline-comments.ini

@@ -1,16 +0,0 @@
-[flake8]
-# This is a flake8 config, there are many like it, but this is mine
-# Disable E123
-# Disable W234
-# Also disable E111
-ignore =
-    E123,
-    W234,
-    E111
-# Exclude foo/
-# Exclude bar/ while we're at it
-# Exclude bogus/
-exclude =
-    foo/,
-    bar/,
-    bogus/

tests/fixtures/config_files/cli-specified.ini

@@ -1,10 +0,0 @@
-[flake8]
-ignore =
-    E123,
-    W234,
-    E111
-exclude =
-    foo/,
-    bar/,
-    bogus/
-quiet = 1

tests/fixtures/config_files/config-with-hyphenated-options.ini

@@ -1,5 +0,0 @@
-[flake8]
-max-line-length = 110
-enable_extensions =
-    H101,
-    H235

tests/fixtures/config_files/no-flake8-section.ini

@@ -1,20 +0,0 @@
-[tox]
-minversion=2.3.1
-envlist = py26,py27,py32,py33,py34,py35,flake8
-
-[testenv]
-deps =
-    mock
-    pytest
-commands =
-    py.test {posargs}
-
-[testenv:flake8]
-skipsdist = true
-skip_install = true
-use_develop = false
-deps =
-    flake8
-    flake8-docstrings
-commands =
-    flake8