Restore Python 3.5 support

Fixes: #48

.github/workflows/release.yml

@@ -70,8 +70,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.5, 3.6, 3.7, 3.8]
         os: [ubuntu-16.04, macos-latest, windows-latest]
+        exclude:
+          # Python 3.5 is unable to properly
+          # find the recent VS tooling
+          # https://bugs.python.org/issue30389
+          - os: windows-latest
+            python-version: 3.5
 
     steps:
     - uses: actions/checkout@v1

.github/workflows/tests.yml

@@ -15,8 +15,14 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.5, 3.6, 3.7, 3.8]
         os: [windows-latest, ubuntu-18.04, macos-latest]
+        exclude:
+          # Python 3.5 is unable to properly
+          # find the recent VS tooling
+          # https://bugs.python.org/issue30389
+          - os: windows-latest
+            python-version: 3.5
 
     steps:
     - uses: actions/checkout@v1

setup.py

@@ -116,19 +116,18 @@ def build_extensions(self):
                 # Support macports on Mac OS X.
                 self.compiler.add_include_dir('/opt/local/include')
         else:
-            self.compiler.add_include_dir(
-                    os.path.join(ROOT, 'vendor/http-parser'))
+            self.compiler.add_include_dir(str(ROOT / 'vendor' / 'http-parser'))
             self.distribution.ext_modules[0].sources.append(
                 'vendor/http-parser/http_parser.c')
 
         super().build_extensions()
 
 
-with open(os.path.join(ROOT, 'README.md')) as f:
+with open(str(ROOT / 'README.md')) as f:
     long_description = f.read()
 
 
-with open(os.path.join(ROOT, 'httptools', '_version.py')) as f:
+with open(str(ROOT / 'httptools' / '_version.py')) as f:
     for line in f:
         if line.startswith('__version__ ='):
             _, _, version = line.partition('=')