Fixed #332 Allow users to reset their password (#335)

* <Added password reset system>

* <Added rspec tests>

* <Fixed code style>

* <Added rescue for invalid smtp configuration>

app/views/user_mailer/password_reset.html.erb

@@ -0,0 +1,32 @@
+<%
+# BigBlueButton open source conferencing system - http://www.bigbluebutton.org/.
+#
+# Copyright (c) 2018 BigBlueButton Inc. and by respective authors (see below).
+#
+# This program is free software; you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free Software
+# Foundation; either version 3.0 of the License, or (at your option) any later
+# version.
+#
+# BigBlueButton is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+# PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
+%>
+
+<h1>Password reset</h1>
+
+<p>Please click the link below to reset your password:</p>
+
+<%= link_to "Reset password", edit_password_reset_url(@user.reset_token,
+                                                      email: @user.email,
+                                                      host: @url) %>
+
+<p>This link will expire in two hours.</p>
+
+<p>
+If you did not request your password to be reset, please ignore this email and
+your password will not be changed.
+</p>