Determines if the environment is a continuous integration service
Value
TRUE if run on AppVeyor or Travis CI, FALSE otherwise
Note
It is possible to fake being on continuous integration service,
in this case GitHub Actions, using:
```r
Sys.setenv(GITHUB_ACTIONS = "I fake being on GitHub Actions")
is_on_ci() # Will be true
```
To undo this, do
```r
Sys.setenv(GITHUB_ACTIONS = "")
is_on_ci() # Will be false
```
Author
Richèl J.C. Bilderbeek
