Update copyright year #69

Job	Run time
docs_examples_latex_pdf (cvode)	1m 27s
docs_examples_latex_pdf (cvodes)	1m 22s
docs_examples_latex_pdf (ida)	1m 23s
docs_examples_sphinx_pdf (arkode)	1m 32s
docs_examples_latex_pdf (idas)	1m 20s
docs_install_guide_pdf	1m 55s
docs_examples_latex_pdf (kinsol)	1m 23s
docs_package_pdf (arkode)	3m 44s
docs_package_pdf (cvode)	2m 56s
docs_package_pdf (cvodes)	3m 41s
docs_package_pdf (ida)	3m 3s
docs_package_pdf (idas)	3m 20s
docs_package_pdf (kinsol)	2m 50s
	29m 56s

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