checkFile
Checks that actualText matches the contents of the file at path
If it doesn't and shouldUpdateTestFixtures is true, update the contents, else throw
Parameters
path
: the path to the file, from the "tests" directory
Checks that actualText matches the contents of the file at path
If it doesn't and shouldUpdateTestFixtures is true, update the contents, else throw
: the path to the file, from the "tests" directory