Hass.io Ingress (#519)

* Hass.io ingress

* Update

* Remove global vars

* Fix

* Fixes

* Fixes

* Upgrade base image to 1.5.1

* Lint

esphome/dashboard/templates/index.html

@@ -16,7 +16,6 @@
 
   <script src="{{ get_static_file_url('materialize-stepper.min.js') }}"></script>
   <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
-  <script>const relative_url = "{{ relative_url }}";</script>
 
   {% if streamer_mode %}
     <style>
@@ -154,7 +153,7 @@
 
 <div id="modal-wizard" class="modal">
   <div class="modal-content">
-    <form action="/wizard.html" method="POST">
+    <form action="./wizard.html" method="POST">
     <ul class="stepper linear">
       <li class="step active">
         <div class="step-title waves-effect">Introduction And Name</div>

esphome/dashboard/templates/login.html

@@ -28,7 +28,7 @@
 <div class="container">
   <div class="row">
     <div class="col card s10 offset-s1 m10 offset-m1 l8 offset-l2">
-      <form action="{{ relative_url }}login" method="post">
+      <form action="./login" method="post">
         <div class="card-content">
           <span class="card-title">Enter credentials</span>
           <p>