Update the license for Github to recognize (#3159)
Update the license for Github to recognize (#3159)

* Create LICENSE

* fix the license

* Delete license.txt

* Rename LICENSE to license.txt

* add others to copyright line
ptosco/rdkit,rdkit/rdkit,greglandrum/rdkit,bp-kelley/rdkit,rdkit/rdkit,ptosco/rdkit,bp-kelley/rdkit,greglandrum/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,ptosco/rdkit,bp-kelley/rdkit,ptosco/rdkit,ptosco/rdkit,greglandrum/rdkit,greglandrum/rdkit,ptosco/rdkit,rdkit/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,ptosco/rdkit,ptosco/rdkit,greglandrum/rdkit,greglandrum/rdkit,greglandrum/rdkit,rdkit/rdkit,rdkit/rdkit,bp-kelley/rdkit,rdkit/rdkit,rdkit/rdkit,greglandrum/rdkit,rdkit/rdkit