Fix some PyLint errors

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)