[WIP] Use PDBInf

[richardjgowers]

No description provided.

[pep8speaks]

Hello @richardjgowers! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file gufe/components/explicitmoleculecomponent.py:

Line 146:80: E501 line too long (100 > 79 characters)
Line 154:80: E501 line too long (97 > 79 characters)
Line 163:80: E501 line too long (95 > 79 characters)
Line 170:80: E501 line too long (107 > 79 characters)

• In the file gufe/components/proteincomponent.py:

Line 87:34: E128 continuation line under-indented for visual indent
Line 110:35: E128 continuation line under-indented for visual indent

• In the file gufe/components/smallmoleculecomponent.py:

Line 11:1: E402 module level import not at top of file

• In the file gufe/tests/conftest.py:

Line 25:80: E501 line too long (125 > 79 characters)
Line 28:80: E501 line too long (109 > 79 characters)
Line 29:80: E501 line too long (110 > 79 characters)
Line 30:80: E501 line too long (110 > 79 characters)
Line 31:80: E501 line too long (110 > 79 characters)
Line 32:80: E501 line too long (110 > 79 characters)
Line 33:80: E501 line too long (110 > 79 characters)
Line 34:80: E501 line too long (111 > 79 characters)
Line 35:80: E501 line too long (114 > 79 characters)
Line 36:80: E501 line too long (110 > 79 characters)
Line 37:80: E501 line too long (112 > 79 characters)
Line 38:80: E501 line too long (110 > 79 characters)
Line 39:80: E501 line too long (109 > 79 characters)
Line 40:80: E501 line too long (111 > 79 characters)
Line 41:80: E501 line too long (109 > 79 characters)
Line 42:80: E501 line too long (111 > 79 characters)
Line 58:80: E501 line too long (85 > 79 characters)