CI: Fix Pycodestyle Warning W605

W605 is a warning for invalid escape sequences.

In python 3.6, Unknown escapes consisting of '\'
and an ASCII letter in regular expressions will
cause an warning.In the upcoming python versions
this would be treated as an error.
Owing to it pycodestyle have added this check for
future Python versions.

The alternative way to escape special characters
now is to append a extra `\` infront of the
sequences. Escape the characters by double backticks.

Fixes coala#2760

bears/c_languages/codeclone_detection/ClangCountingConditions.py

@@ -245,17 +245,17 @@ def in_sum(stack):  # pragma nt: no cover
 def in_product(stack):  # pragma nt: no cover
     """
     A counting condition returning true if the variable is used in a product
-    statement, i.e. within the operators \*, /, % and their associated compound
-    operators.
+    statement, i.e. within the operators \\*, /, % and their associated
+    compound operators.
     """
     return _stack_contains_operators(stack, ['*', '/', '%', '*=', '/=', '%='])
 
 
 def in_binary_operation(stack):  # pragma nt: no cover
     """
     A counting condition returning true if the variable is used in a binary
-    operation, i.e. within the operators \|, & and their associated compound
-    operators.
+    operation, i.e. within the operators \\|, & and their associated
+    compound operators.
     """
     return _stack_contains_operators(stack, ['&', '|', '&=', '|='])
 

bears/vcs/git/GitCommitBear.py

@@ -35,7 +35,7 @@ def check_github_pull_request_temporary_merge_commit(self):
         """
         This function creates a git command to fetch the
         unmerged parent commit shortlog from a commit generated
-        by GitHub in a refs/pull/(\d+)/merge git remote reference.
+        by GitHub in a refs/pull/(\\d+)/merge git remote reference.
         Visit https://github.com/travis-ci/travis-ci/issues/8400
         for more details.