Dockerfile/PEP8 update

[pointlessone]

Dockerfile changes

• Base image switched to Alpine. The new image is almost 11x smaller (63.97 MiB vs 693 MiB).

PEP8 Changelog

2.2.0 (2016-11-14)

Bugs:

• Fixed E305 regression caused by Require two blank lines *after* a def/class too PyCQA/pycodestyle#400;
  Fix E305 regression in 2.1.0 due to fix for #400 PyCQA/pycodestyle#593

2.1.0 (2016-11-04)

Changes:

• Report E302 for blank lines before an "async def";
  Report E302 for blank lines before an "async def" PyCQA/pycodestyle#556
• Update our list of tested and supported Python versions which are 2.6,
  2.7, 3.2, 3.3, 3.4 and 3.5 as well as the nightly Python build and
  PyPy.
• Report E742 and E743 for functions and classes badly named 'l', 'O',
  or 'I'.
• Report E741 on 'global' and 'nonlocal' statements, as well as
  prohibited single-letter variables.
• Deprecated use of [pep8] section name in favor of [pycodestyle];
  Check for both [pep8] and [pycodestyle] config sections. PyCQA/pycodestyle#591

Bugs:

• Fix opt_type AssertionError when using Flake8 2.6.2 and pycodestyle;
  Choice type parameters raise AssertionError for config files PyCQA/pycodestyle#561
• Require two blank lines after toplevel def, class;
  Fix Issue 400: Require two blank lines after toplevel def, class PyCQA/pycodestyle#536
• Remove accidentally quadratic computation based on the number of
  colons. This will make pycodestyle faster in some cases;
  Fixing compound_statement not to be quadratic in # of :s PyCQA/pycodestyle#314

2.0.0 (2016-05-31)

Changes:

• Added tox test support for Python 3.5 and pypy3
• Added check E275 for whitespace on from ... import ... lines;
  complain about missing space before opening parentheses of import statement PyCQA/pycodestyle#489 / complain about missing space before opening parentheses of import statement PyCQA/pycodestyle#491
• Added W503 to the list of codes ignored by default ignore list;
  Update handling of breaking around binary operators: W503 vs W504 PyCQA/pycodestyle#498
• Removed use of project level .pep8 configuration file;
  Remove deprecated .pep8 config file PyCQA/pycodestyle#364

Bugs:

• Fixed bug with treating ~ operator as binary; Fix problem with treating ~ operator as binary. PyCQA/pycodestyle#383
  / Tilde is treated as binary operator PyCQA/pycodestyle#384
• Identify binary operators as unary; Unary - reporting as W503 PyCQA/pycodestyle#484 /
  Identify binary operators used as unary operators PyCQA/pycodestyle#485

1.7.0 (2016-01-12)

Changes:

• Reverted the fix in defined config overwritten by config further up directory tree PyCQA/pycodestyle#368, "options passed on command
  line are only ones accepted" feature. This has many unintended
  consequences in pep8 and flake8 and needs to be reworked when I have
  more time.
• Added support for Python 3.5. (Issue Support Python 3.5 PyCQA/pycodestyle#420 &
  fix BytesWarning on Python 3 PyCQA/pycodestyle#459)
• Added support for multi-line config_file option parsing. (Issue
  Multi-line ignore parsing in config_file PyCQA/pycodestyle#429)
• Improved parameter parsing. (Issues Support Python 3.5 PyCQA/pycodestyle#420 &
  Correct _get_parameters. PyCQA/pycodestyle#456)

Bugs:

• Fixed BytesWarning on Python 3. (Issue fix BytesWarning on Python 3 PyCQA/pycodestyle#459)

[gdiggs]

LGTM