Support anonymous access

mantis.psm1

@@ -536,10 +536,15 @@ function Use-MantisInstance {
 
 function getCommonHeaders {
   $headers = @{
-    "Authorization" = $instance.token
     "User-Agent" = "MantisPowerShell"
   }
 
+  # Anonymous access instances won't have a token, so check before
+  # attempting to add the header.
+  if( ($instance.PSobject.Properties.name -match "token") ) {
+    $headers["Authorization"] = $instance.token
+  }
+
   return $headers
 }
 

readme.md

@@ -35,17 +35,29 @@ Create API Token as per the following [article](https://support.mantishub.com/hc
 Create `~/.mantis.companyname.json` with contents like the one below including the appropriate URL and logical
 name for the instance.
 
+Example for authenticated instance:
 ```json
 {
   "uri": "https://companyname.com/mantisbt/",
   "token": "YjQlU7OI0D..........sWC1vGaAuq3Q"
 }
 ```
 
+Example for anonymous access
+```json
+{
+  "uri": "https://companyname.com/mantisbt/"
+}
+```
+
 Select the instance for all future commands:
 
     Use-MantisInstance companyname
 
+Note that the selected instance will be persisted on disk, hence, it will persist across PowerShell
+restarts.  This is done by copying `.mantis.company.json` to `.mantis.json`.  So if the configuration
+is changed, re-run the command `Use-MantisInstance`.
+
 ## Get Logged In User Info
 
     Get-MantisUser -me