Integrate flake8 and coverage.py with tox (#141)

Fixes #38

.coveragerc

+[run]
+branch = True
+omit = 
+    # omit the codegen because of deprecation
+    astor/codegen.py
+    .tox/*
+[report]
+show_missing = True

AUTHORS

@@ -16,3 +16,4 @@ And with some modifications based on Armin's code:
 * Kodi Arfer <git@arfer.net>
 * Felix Yan <felixonmars@archlinux.org>
 * Chris Rink <chrisrink10@gmail.com>
+* Batuhan Taskaya <batuhanosmantaskaya@gmail.com>

astor/code_gen.py

@@ -23,7 +23,7 @@ import sys
 
 from .op_util import get_op_symbol, get_op_precedence, Precedence
 from .node_util import ExplicitNodeVisitor
-from .string_repr import pretty_string, string_triplequote_repr
+from .string_repr import pretty_string
 from .source_repr import pretty_source
 
 
@@ -155,7 +155,6 @@ class SourceGenerator(ExplicitNodeVisitor):
         AST = ast.AST
 
         visit = self.visit
-        newline = self.newline
         result = self.result
         append = result.append
 

astor/rtrip.py

@@ -81,7 +81,7 @@ def convert(srctree, dsttree=dsttree, readonly=False, dumpall=False,
 
         try:
             dsttxt = to_source(srcast)
-        except:
+        except Exception:
             if not ignore_exceptions:
                 raise
             dsttxt = ''

astor/source_repr.py

@@ -101,8 +101,8 @@ def wrap_line(line, maxline=79, result=[], count=count):
     pos = indent + count(first)
     indentation += '    '
     indent += 4
-    if indent >= maxline/2:
-        maxline = maxline/2 + indent
+    if indent >= maxline / 2:
+        maxline = maxline / 2 + indent
 
     for sg, nsg in zip(splittable, unsplittable[1:]):
 

astor/string_repr.py

@@ -107,6 +107,6 @@ def pretty_string(s, embedded, current_line, uni_lit=False,
     try:
         if eval(fancy) == s and '\r' not in fancy:
             return fancy
-    except:
+    except Exception:
         pass
     return default

requirements-tox.txt

 nose>=1.3.0
+flake8>=3.7.0
+coverage>=4.5.0

tox.ini

 [tox]
-envlist = py27, py34, py35, py36, py37, py38, pypy, pypy3.5
+envlist = 
+    py{27, 34, 35, 36, 37, 38, py, py3.5}
+    lint
 skipsdist = True
+skip_missing_interpreters = true
 
 [testenv]
 usedevelop = True
-commands = nosetests -v --nocapture {posargs}
+commands = 
+        coverage run {envbindir}/nosetests -v --nocapture {posargs}
+        coverage report
 deps =
  -rrequirements-tox.txt
  py27,pypy: unittest2
+
+[testenv:lint]
+deps = flake8
+commands = flake8 astor/
+
+[flake8]
+ignore = E114, E116, E501, W504
+
+[travis]
+python =
+  3.7: py37, lint