SSL: CERTIFICATE_VERIFY_FAILED when using any search engine

**Describe the bug**

SSL: CERTIFICATE_VERIFY_FAILED when using any search engine.

**To Reproduce**
Steps to reproduce the behavior:
1. Open python console to
2. Import search_engine_parser
3. Search using i.e. duckduckgo Engine :
~~~python
eng = DuckDuckGoSearch()
results = eng.search('something', page)
~~~
5. See error

~~~bash
File "/home/valerino/work/test_search/test_searchengines.py", line 187, in search
results = eng.search(entity, page)
File "/home/valerino/.local/lib/python3.8/site-packages/search_engine_parser/core/base.py", line 284, in search
soup = loop.run_until_complete(
File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
return future.result()
File "/home/valerino/.local/lib/python3.8/site-packages/search_engine_parser/core/base.py", line 212, in get_soup
html = await self.get_source(url, cache, proxy, proxy_auth)
File "/home/valerino/.local/lib/python3.8/site-packages/search_engine_parser/core/base.py", line 194, in get_source
raise Exception('ERROR: {}\n'.format(exc))
Exception: ERROR: Cannot connect to host www.duckduckgo.com:443 ssl:True [SSLCertVerificationError: (1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1131)')]
~~~

**Desktop (please complete the following information):**
- OS: Linux Mint 20.3 Una
- Python Version 3.8
- Search-engine-parser version 0.6.6