Drop Python 3.4 support (vc++ 10 is not available on appveyor)

appveyor.yml

@@ -15,16 +15,6 @@ environment:
     secure: bBLT+ICiuwrkYZEBrL++Jw==
 
   matrix:
-    - PYTHON: "C:\\Python34"
-      PYTHON_VERSION: "3.4.x"
-      PYTHON_ARCH: "32"
-      LIBTGVOIP_JOB: "Environment: PLATFORM=x86"
-
-    - PYTHON: "C:\\Python34-x64"
-      PYTHON_VERSION: "3.4.x"
-      PYTHON_ARCH: "64"
-      LIBTGVOIP_JOB: "Environment: PLATFORM=x64"
-
     - PYTHON: "C:\\Python35"
       PYTHON_VERSION: "3.5.x"
       PYTHON_ARCH: "32"
@@ -58,14 +48,14 @@ environment:
 clone_folder: c:\projects\pytgvoip
 
 install:
-  - ps: if (-not(Test-Path($env:PYTHON))) { & appveyor\install.ps1 }
+  - ps: if (-not(Test-Path($env:PYTHON))) { & ci_scripts\install.ps1 }
   - set PATH=%PYTHON%;%PYTHON%\Scripts;%PATH%
   - python --version
   - python -c "import struct; print(struct.calcsize('P') * 8)"
   - python -m pip install wheel pip twine -U
   - appveyor DownloadFile "https://ci.appveyor.com/api/projects/bakatrouble/libtgvoip/artifacts/out/Release/libtgvoip.dll.zip?job=%LIBTGVOIP_JOB%"
   - 7z x libtgvoip.dll.zip
-  - git submodule update --init --recursive
+  - mkdir 3rdparty
   - git clone https://github.com/bakatrouble/libtgvoip/ 3rdparty/libtgvoip
   - cd 3rdparty/libtgvoip
   - git checkout msvc_static

setup.py

@@ -177,7 +177,7 @@ def get_data_files():
         'Community': 'https:/t.me/pytgvoip',
         'Source': 'https://github.com/bakatrouble/pytgvoip',
     },
-    python_required='~=3.4',
+    python_required='~=3.5',
     ext_modules=ext_modules,
     packages=['tgvoip'],
     package_dir={'tgvoip': os.path.join('src', 'tgvoip')},
@@ -193,7 +193,6 @@ def get_data_files():
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3 :: Only',
-        'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',