Change pyproject.toml to be SPDX compliant

Author: Michael-E-Rose

pyproject.toml

@@ -8,7 +8,7 @@ authors = [{name = "'John Kitchin and Michael E. Rose", email = "Michael.Ernst.R
 maintainers = [{name = "Michael E. Rose", email = "Michael.Ernst.Rose@gmail.com"}]
 description = "Python-based API-Wrapper to access Scopus and ScienceDirect"
 readme = "README.rst"
-license = {text = "MIT"}
+license = "MIT"
 dependencies = [
     "requests",
     "tqdm",
@@ -18,7 +18,6 @@ classifiers = [
     "Development Status :: 5 - Production/Stable",
     "Intended Audience :: Science/Research",
     "Intended Audience :: Developers",
-    "License :: OSI Approved :: MIT License",
     "Natural Language :: English",
     "Operating System :: OS Independent",
     "Programming Language :: Python :: 3.9",