Add tests to the package

[gdequeiroz]

So far we only have 2 tests: test-get_events.R test-find_groups.R.

We need to add tests to other functions (https://github.com/rladies/meetupr/tree/master/R)

[missaugustina]

Also see issue #31 and PR #32

I'm working on tests and if my changes are approved, would like to pair with others who are looking for ways to contribute.

[gdequeiroz]

@missaugustina I changed the label from "help wanted" to " work in progress" since you are working on that. :)

[missaugustina]

I will add stubs similar to what I did for remaining tests needed for the other ones. This will make it easier for folks to see what tests are needed and to make easy contributions.

[maelle]

I need to add more tests & vcr fixtures. @ledell I wouldn't want us to submit the package to CRAN before we have something like 75% coverage. Should be achievable.

> covr::package_coverage()
meetupr Coverage: 28.47%
R/deprecated.R: 0.00%
R/get_boards.R: 0.00%
R/get_event_attendees.R: 0.00%
R/get_event_comments.R: 0.00%
R/get_event_rsvps.R: 0.00%
R/get_members.R: 0.00%
R/uq-filename.R: 0.00%
R/utils-renv.R: 0.00%
R/zzz.R: 8.33%
R/meetup_auth.R: 14.88%
R/internals.R: 53.12%
R/find_groups.R: 94.12%
R/get_events.R: 100.00%