Allow setting username and hostname location in prompt

Defaults to the style for the original pure for zsh, as seen in sindresorhus/pure#126

fish_prompt.fish

@@ -28,6 +28,12 @@ __pure_set_default pure_username_color $pure_color_gray
 __pure_set_default pure_host_color $pure_color_gray
 __pure_set_default pure_root_color $pure_color_normal
 
+# Determines whether the username and host are shown at the begining or end
+# 0 - end of prompt, default
+# 1 - start of prompt
+# Any other value defaults to the default behaviour
+__pure_set_default pure_user_host_location 0
+
 # Max execution time of a process before its run time is shown when it exits
 __pure_set_default pure_command_max_exec_time 5
 
@@ -68,8 +74,9 @@ function fish_prompt
     set user_and_host "$user$pure_color_gray@$pure_host_color$host$pure_color_normal "
   end
 
-  # Format user and host on prompt output
-  set prompt $prompt $user_and_host
+  if test $pure_user_host_location -eq 1
+    set prompt $prompt $user_and_host
+  end
 
   # Format current folder on prompt output
   set prompt $prompt "$pure_color_blue$current_folder$pure_color_normal "
@@ -126,6 +133,10 @@ function fish_prompt
     set prompt $prompt "$pure_color_gray$git_branch_name$git_dirty$pure_color_normal\t$pure_color_cyan$git_arrows$pure_color_normal"
   end
 
+  if test $pure_user_host_location -ne 1
+    set prompt $prompt $user_and_host
+  end
+
   set prompt $prompt "\n$color_symbol$pure_symbol_prompt$pure_color_normal "
 
   echo -e -s $prompt