Drop redundant -X POST curl flags

Should reduce warnings.  Fixes #26

Author: jhunt

ci/release_notes.md

@@ -3,3 +3,6 @@
 - The `text` field of attachments now interpolates environment
   variables from the container environment (i.e. BUILD_* et al).
   Fixes #25
+
+- Drop `-X POST` curl flags to silence warnings from curl.
+  Fixes #26

out

@@ -128,13 +128,13 @@ EOF
   elif [[ "$silent" == "true" ]]
   then
     echo "Using silent output"
-    curl -s -X POST --data-urlencode "payload=${compact_body}" ${CURL_OPTION} "${webhook_url}"
+    curl -s --data-urlencode "payload=${compact_body}" ${CURL_OPTION} "${webhook_url}"
   elif [[ ${redact_hook} == "true" ]]
   then
     url_path="$(echo ${webhook_url} | sed -e "s/https\{0,1\}:\/\/[^\/]*\(\/[^?&#]*\).*/\1/")"
-    curl -v -X POST --data-urlencode "payload=${compact_body}" ${CURL_OPTION} "${webhook_url}" 2>&1 | sed -e "s#${url_path}#***WEBHOOK URL REDACTED***#g"
+    curl -v --data-urlencode "payload=${compact_body}" ${CURL_OPTION} "${webhook_url}" 2>&1 | sed -e "s#${url_path}#***WEBHOOK URL REDACTED***#g"
   else
-    curl -v -X POST --data-urlencode "payload=${compact_body}" ${CURL_OPTION} "${webhook_url}" | sed -e "s#${url_path}#***WEBHOOK URL REDACTED***#g"
+    curl -v --data-urlencode "payload=${compact_body}" ${CURL_OPTION} "${webhook_url}" | sed -e "s#${url_path}#***WEBHOOK URL REDACTED***#g"
   fi
 else
   text="$(echo "" | jq -R -s .)"