Fix typos

features/issue.feature

@@ -644,7 +644,7 @@ Feature: hub issue
       """
     Then I successfully run `hub issue update 1337 -M 42`
 
-  Scenario: Upate an issue's milestone by name
+  Scenario: Update an issue's milestone by name
     Given the GitHub API server:
       """
       get('/repos/github/hub/milestones') {

script/coverage

@@ -52,7 +52,7 @@ summarize() {
   echo "Code coverage: $total_coverage"
   local result="$(bc <<<"${total_coverage%\%} < $min_coverage")"
   if [ "$result" -eq 1 ]; then
-    echo "Error: coverage dropped below the minimum treshold of ${min_coverage}%!"
+    echo "Error: coverage dropped below the minimum threshold of ${min_coverage}%!"
     if [ -n "$CI" ]; then
       html_result="${HUB_COVERAGE%.out}.html"
       html_result="${html_result#$PWD/}"