added test for duckduckgo

[pep8speaks]

Hello @shreenaathia! Thanks for updating the PR.

• In the file pySearch.py, following are the PEP8 issues :

  Line 1:1: E265 block comment should start with '# ' Line 6:80: E501 line too long (124 > 79 characters) Line 7:80: E501 line too long (153 > 79 characters) Line 8:80: E501 line too long (88 > 79 characters) Line 14:27: W292 no newline at end of file

• In the file search.py, following are the PEP8 issues :

  Line 10:32: E251 unexpected spaces around keyword / parameter equals Line 10:34: E251 unexpected spaces around keyword / parameter equals Line 10:49: E251 unexpected spaces around keyword / parameter equals Line 10:51: E251 unexpected spaces around keyword / parameter equals Line 10:70: E251 unexpected spaces around keyword / parameter equals Line 10:72: E251 unexpected spaces around keyword / parameter equals Line 17:5: E265 block comment should start with '# ' Line 19:5: E265 block comment should start with '# ' Line 22:5: E265 block comment should start with '# ' Line 24:5: E265 block comment should start with '# ' Line 27:5: E265 block comment should start with '# ' Line 28:1: W293 blank line contains whitespace Line 29:5: E265 block comment should start with '# ' Line 32:5: E265 block comment should start with '# ' Line 42:9: E265 block comment should start with '# ' Line 43:80: E501 line too long (105 > 79 characters) Line 45:24: E703 statement ends with a semicolon Line 45:25: W291 trailing whitespace Line 46:80: E501 line too long (81 > 79 characters) Line 48:49: E231 missing whitespace after ',' Line 50:9: E265 block comment should start with '# ' Line 51:12: E225 missing whitespace around operator Line 55:9: E265 block comment should start with '# ' Line 56:55: E203 whitespace before ':' Line 57:1: W293 blank line contains whitespace Line 61:9: E265 block comment should start with '# ' Line 64:24: W291 trailing whitespace Line 67:4: E114 indentation is not a multiple of four (comment) Line 69:5: E265 block comment should start with '# ' Line 70:1: W293 blank line contains whitespace Line 81:10: E114 indentation is not a multiple of four (comment) Line 82:5: E265 block comment should start with '# ' Line 83:1: W293 blank line contains whitespace Line 84:1: E265 block comment should start with '# ' Line 84:14: W292 no newline at end of file

• In the file tests/test_search_duckduckgo.py, following are the PEP8 issues :

  Line 5:1: E302 expected 2 blank lines, found 1 Line 11:1: W293 blank line contains whitespace Line 11:1: W391 blank line at end of file