Removed warnings (invalid escape sequence for docstring & cython issue)

boundaries/createindexlist.py

@@ -5,7 +5,7 @@ import warnings
 try:
     import pyximport
 
-    pyximport.install()
+    pyximport.install(language_level=3)
     from pystencils.boundaries.createindexlistcython import create_boundary_index_list_2d, create_boundary_index_list_3d
 
     cython_funcs_available = True

cpu/msvc_detection.py

@@ -35,7 +35,7 @@ def get_environment(version_specifier, arch='x64'):
 def find_latest_msvc_version_using_environment_variables():
     import re
     # noinspection SpellCheckingInspection
-    regex = re.compile('VS(\d\d)\dCOMNTOOLS')
+    regex = re.compile(r'VS(\d\d)\dCOMNTOOLS')
     versions = []
     for key, value in os.environ.items():
         match = regex.match(key)