expectation_lint() misbehaves when lint number larger than expected [patch]

[fangly]

Hi,
When the number of lints is larger than the expected number, expectation_lint() passes 2 strings instead of 1 to testthat::expect, which caused an error.
This patch fixes the issue: 0001-Fixed-expectation_lint-for-when-lint-number-expected.zip
Best,
Florent

[fangly]

Note: This patch is based on a git repo freshly initialized from lintr's master branch on 24 Oct (unfortunately, a firewall blocks the ports needed for a git clone, pull, etc).

[fangly]

Fixed in #214