Merge pull request #270 from sendgrid/troubleshooting

Adding troubleshooting section

README.md

@@ -195,6 +195,10 @@ Quick links:
 - [Sign the CLA to Create a Pull Request](https://github.com/sendgrid/sendgrid-php/blob/master/CONTRIBUTING.md#cla)
 - [Improvements to the Codebase](https://github.com/sendgrid/sendgrid-php/blob/master/CONTRIBUTING.md#improvements_to_the_codebase)
 
+# Troubleshooting
+
+Please see our [troubleshooting guide](https://github.com/sendgrid/sendgrid-php/blob/master/TROUBLESHOOTING.md) for common library issues.
+
 # About
 
 sendgrid-php is guided and supported by the SendGrid [Developer Experience Team](mailto:dx@sendgrid.com).

TROUBLESHOOTING.md

@@ -0,0 +1,89 @@
+If you have a non-library SendGrid issue, please contact our [support team](https://support.sendgrid.com).
+
+If you can't find a solution below, please open an [issue](https://github.com/sendgrid/sendgrid-php/issues).
+
+
+## Table of Contents
+
+* [Migrating from v2 to v3](#migrating)
+* [Continue Using v2](#v2)
+* [Testing v3 /mail/send Calls Directly](#testing)
+* [Error Messages](#error)
+* [Versions](#versions)
+* [Environment Variables and Your SendGrid API Key](#environment)
+* [Using the Package Manager](#package-manager)
+
+<a name="migrating"></a>
+## Migrating from v2 to v3
+
+Please review [our guide](https://sendgrid.com/docs/Classroom/Send/v3_Mail_Send/how_to_migrate_from_v2_to_v3_mail_send.html) on how to migrate from v2 to v3.
+
+<a name="v2"></a>
+## Continue Using v2
+
+[Here](https://github.com/sendgrid/sendgrid-php/tree/75970eb82f5629e66db4d6da08ff7ef0c507e9b0) is the last working version with v2 support.
+
+Using composer:
+
+```json
+{
+  "require": {
+    "sendgrid/sendgrid": "~3.2"
+  }
+}
+```
+
+Download packaged zip [here](https://sendgrid-open-source.s3.amazonaws.com/sendgrid-php/versions/sendgrid-php-75970eb.zip).
+
+<a name="testing"></a>
+## Testing v3 /mail/send Calls Directly
+
+[Here](https://sendgrid.com/docs/Classroom/Send/v3_Mail_Send/curl_examples.html) are some cURL examples for common use cases.
+
+<a name="error"></a>
+## Error Messages
+
+To read the error message returned by SendGrid's API:
+
+```php
+try {
+    $response = $sendgrid->client->mail()->send()->post($mail);
+} catch (Exception $e) {
+    echo 'Caught exception: ',  $e->getMessage(), "\n";
+}
+```
+
+<a name="versions"></a>
+## Versions
+
+We follow the MAJOR.MINOR.PATCH versioning scheme as described by [SemVer.org](http://semver.org). Therefore, we recommend that you always pin (or vendor) the particular version you are working with to your code and never auto-update to the latest version. Especially when there is a MAJOR point release, since that is guarenteed to be a breaking change. Changes are documented in the [CHANGELOG](https://github.com/sendgrid/sendgrid-php/blob/master/CHANGELOG.md) and [releases](https://github.com/sendgrid/sendgrid-php/releases) section.
+
+<a name="environment"></a>
+## Environment Variables and Your SendGrid API Key
+
+All of our examples assume you are using [environment variables](https://github.com/sendgrid/sendgrid-php#setup-environment-variables) to hold your SendGrid API key.
+
+If you choose to add your SendGrid API key directly (not recommended):
+
+`$apiKey = getenv('SENDGRID_API_KEY');`
+
+becomes
+
+`$apiKey = 'SENDGRID_API_KEY';`
+
+In the first case SENDGRID_API_KEY is in reference to the name of the environment variable, while the second case references the actual SendGrid API Key.
+
+<a name="package-manager"></a>
+## Using the Package Manager
+
+We upload this library to [Packagist](https://packagist.org/packages/sendgrid/sendgrid) whenever we make a release. This allows you to use [composer](https://getcomposer.org) for easy installation.
+
+In most cases we recommend you download the latest version of the library, but if you need a different version, please use:
+
+```json
+{
+  "require": {
+    "sendgrid/sendgrid": "~X.X.X"
+  }
+}
+```