Making `ard_survey_svycontinuous()` a S3 method #42

All 39 tests pass, 18 skipped in 8s

1 files ±0 57 suites ±0 8s ⏱️ -1s
57 tests ±0 39 ✅ ±0 18 💤 ±0 0 ❌ ±0
148 runs ±0 119 ✅ ±0 29 💤 ±0 0 ❌ ±0

Results for commit 5c55508. ± Comparison against earlier commit 4419876.