Trims output length to avoid hitting github 2Mb limitation (#206)

Co-authored-by: ahub <ahub@riseup.net>

src/model/results-check.ts

@@ -76,6 +76,14 @@ const ResultsCheck = {
     const pullRequest = github.context.payload.pull_request;
     const headSha = (pullRequest && pullRequest.head.sha) || github.context.sha;
 
+    const maxLen = 65534;
+    if(output.length > maxLen)
+    {
+      core.warning(`Output too long (${output.length}) truncating to ${maxLen}`);
+      output = output.substring(0, maxLen);
+    }
+
+
     core.info(`Posting results for ${headSha}`);
     const createCheckRequest = {
       ...github.context.repo,