Dalby

Minor changes

• Update documentation for get_GSOD() when using station parameter
• Edit unit tests to enhance coverage
• Edit paper.md for submission to JOSS
• Add pdf version of paper
• Remove extra packages listed as dependencies that are no longer necessary
• Correct Working_with_spatial_and_climate_data.Rmd where it was missing the first portion of documentation to download data for Philippines and thus examples did not work