Add password reset

Closes #15

Gemfile.lock

@@ -26,6 +26,7 @@ GEM
     chartkick (5.1.4)
     concurrent-ruby (1.3.5)
     connection_pool (2.5.0)
+    date (3.4.1)
     drb (2.2.1)
     erubi (1.13.1)
     forwardable (1.3.2)
@@ -39,10 +40,25 @@ GEM
       concurrent-ruby (~> 1.0)
     locale (2.1.4)
     logger (1.6.6)
+    mail (2.8.1)
+      mini_mime (>= 0.1.1)
+      net-imap
+      net-pop
+      net-smtp
+    mini_mime (1.1.5)
     mini_portile2 (2.8.8)
     minitest (5.25.5)
     mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
+    net-imap (0.5.8)
+      date
+      net-protocol
+    net-pop (0.1.2)
+      net-protocol
+    net-protocol (0.2.2)
+      timeout
+    net-smtp (0.5.1)
+      net-protocol
     nio4r (2.7.4)
     prime (0.1.3)
       forwardable
@@ -76,8 +92,6 @@ GEM
     singleton (0.3.0)
     sqlite3 (2.6.0)
       mini_portile2 (~> 2.8.0)
-    sqlite3 (2.6.0-arm64-darwin)
-    sqlite3 (2.6.0-x86_64-darwin)
     text (1.3.1)
     tilt (2.6.0)
     timeout (0.4.3)
@@ -96,6 +110,7 @@ DEPENDENCIES
   chartkick
   forwardable (= 1.3.2)
   gettext
+  mail
   puma
   rackup
   rake