Error types need to converted into booleans

[jannepeltola]

I noticed that jsonlint return values don’t work properly. Code outside this method treats these values as booleans.

Steps to reproduce:

tmp $ cat test.json
{
    "foo" : [ 1,2,3]
}
tmp $ jsonlint test.json
test.json: ok
tmp $ echo $?
0
tmp $ cat test.json
{
    "foo" : [ 1,2,3
}
tmp $ jsonlint test.json
test.json:3:0: Error: Expected a ']' but saw '}'
   |  At line 3, column 0, offset 22
   |  Array started at line 2, column 12, offset 14
test.json: has errors
tmp $ echo $?
0

$? should be 1, and after applying the attached patch it is.

[dmeranda]

I have opened Issue #12 to track this bug; you may subscribe to it if you want. This bug has been reported by multiple people and will be fixed shortly. Thanks for your suggested patch.