Add test

[ecodata1]

Add testing.

1. Fork project and open in Rstudio
2. Read https://r-pkgs.org/testing-basics.html#create-a-test
3. Open get-observations.R file in R directory
4. In console, try usethis::test()
5. Should create a new test file
6. Write test file to do get some results and test data match expectation