[BUG]Pip 安装提示需要C++14.0以上生成工具

**问题描述（Question description）**
```
Complete output from command python setup.py egg_info:
Testing support for clang
Traceback (most recent call last):
File "", line 1, in
File "C:\Users\Rosefun\AppData\Local\Temp\pip-install-lx38hx1j\pycryptodome\setup.py", line 468, in
set_compiler_options(package_root, ext_modules)
File "C:\Users\Rosefun\AppData\Local\Temp\pip-install-lx38hx1j\pycryptodome\compiler_opt.py", line 341, in set_compiler_options
clang = compiler_is_clang()
File "C:\Users\Rosefun\AppData\Local\Temp\pip-install-lx38hx1j\pycryptodome\compiler_opt.py", line 251, in compiler_is_clang
return test_compilation(source, msg="clang")
File "C:\Users\Rosefun\AppData\Local\Temp\pip-install-lx38hx1j\pycryptodome\compiler_opt.py", line 82, in test_compilation
objects = compiler.compile([fname], extra_postargs=extra_cc_options)
File "D:\DeepLearningInstall\anaconda3.5\lib\distutils\_msvccompiler.py", line 345, in compile
self.initialize()
File "D:\DeepLearningInstall\anaconda3.5\lib\distutils\_msvccompiler.py", line 238, in initialize
vc_env = _get_vc_env(plat_spec)
File "D:\DeepLearningInstall\anaconda3.5\lib\site-packages\setuptools\msvc.py", line 312, in msvc14_get_vc_env
return _msvc14_get_vc_env(plat_spec)
File "D:\DeepLearningInstall\anaconda3.5\lib\site-packages\setuptools\msvc.py", line 267, in _msvc14_get_vc_env
"Unable to find vcvarsall.bat"
distutils.errors.DistutilsPlatformError: Microsoft Visual C++ 14.0 or greater is required. Get it with "Microsoft C++ Build Tools": https://visualstudio.microsoft.com/visual-cpp-build-tools/

----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in C:\Users\Rosefun\AppData\Local\Temp\pip-install-lx38hx1j\pycryptodome\
```