Fix some PyLint errors

.pylintrc

@@ -1,23 +1,12 @@
 [MESSAGES CONTROL]
-
-# Only show warnings with the listed confidence levels. Leave empty to show
-# all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED
-confidence=
-
-# Enable the message, report, category or checker with the given id(s). You can
-# either give multiple identifier separated by comma (,) or put this option
-# multiple time. See also the "--disable" option for examples.
-#enable=
-
-# Disable the message, report, category or checker with the given id(s). You
-# can either give multiple identifiers separated by comma (,) or put this
-# option multiple times (only on the command line, not in the configuration
-# file where it should appear only once).You can also use "--disable=all" to
-# disable everything first and then reenable specific checks. For example, if
-# you want to run only the similarities checker, you can use "--disable=all
-# --enable=similarities". If you want to run only the classes checker, but have
-# no Warning level messages displayed, use"--disable=all --enable=classes
-# --disable=W"
-# disable=import-star-module-level,old-octal-literal,oct-method,print-statement,unpacking-in-except,parameter-unpacking,backtick,old-raise-syntax,old-ne-operator,long-suffix,dict-view-method,dict-iter-method,metaclass-assignment,next-method-called,raising-string,indexing-exception,raw_input-builtin,long-builtin,file-builtin,execfile-builtin,coerce-builtin,cmp-builtin,buffer-builtin,basestring-builtin,apply-builtin,filter-builtin-not-iterating,using-cmp-argument,useless-suppression,range-builtin-not-iterating,suppressed-message,no-absolute-import,old-division,cmp-method,reload-builtin,zip-builtin-not-iterating,intern-builtin,unichr-builtin,reduce-builtin,standarderror-builtin,unicode-builtin,xrange-builtin,coerce-method,delslice-method,getslice-method,setslice-method,input-builtin,round-builtin,hex-method,nonzero-method,map-builtin-not-iterating
-
-disable=missing-docstring,invalid-name,too-few-public-methods,redefined-variable-type,similarities,unsupported-membership-test,unsubscriptable-object,ungrouped-imports,cyclic-import,superfluous-parens,useless-object-inheritance,useless-import-alias,fixme
+disable=
+    missing-docstring,
+    ungrouped-imports,
+    invalid-name,
+    cyclic-import,
+    duplicate-code,
+    superfluous-parens,
+    too-few-public-methods,
+    useless-object-inheritance,
+    useless-import-alias,
+    fixme

platformio/commands/upgrade.py

@@ -43,11 +43,10 @@ def cli(dev):
              get_pip_package(to_develop)], ["platformio", "--version"])
 
     cmd = None
-    r = None
+    r = {}
     try:
         for cmd in cmds:
             cmd = [util.get_pythonexe_path(), "-m"] + cmd
-            r = None
             r = util.exec_command(cmd)
 
             # try pip with disabled cache

platformio/exception.py

@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# pylint: disable=not-an-iterable
-
 
 class PlatformioException(Exception):
 

platformio/managers/lib.py

@@ -164,7 +164,7 @@ class LibraryManager(BasePkgManager):
 
         semver_spec = self.parse_semver_spec(
             requirements) if requirements else None
-        item = None
+        item = {}
 
         for v in versions:
             semver_new = self.parse_semver_version(v['name'])

platformio/util.py

@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# pylint: disable=too-many-ancestors
-
 import json
 import os
 import platform
@@ -464,7 +462,7 @@ def _get_api_result(
         auth=None):
     from platformio.app import get_setting
 
-    result = None
+    result = {}
     r = None
     verify_ssl = sys.version_info >= (2, 7, 9)