Update text to change auth flows

src/components/structures/auth/ForgotPassword.js

@@ -257,7 +257,7 @@ module.exports = React.createClass({
                     { serverConfigSection }
                     { errorText }
                     <a className="mx_Auth_changeFlow" onClick={this.onLoginClick} href="#">
-                        { _t('Return to login screen') }
+                        { _t('Sign in instead') }
                     </a>
                 </div>
             </div>

src/components/structures/auth/Login.js

@@ -565,7 +565,7 @@ module.exports = React.createClass({
                     { this.componentForStep(this.state.currentFlow) }
                     { serverConfig }
                     <a className="mx_Auth_changeFlow" onClick={this.onRegisterClick} href="#">
-                        { _t('Create an account') }
+                        { _t('Create account') }
                     </a>
                     { loginAsGuestJsx }
                 </AuthBody>

src/components/structures/auth/Registration.js

@@ -466,7 +466,7 @@ module.exports = React.createClass({
         if (!this.state.doingUIAuth) {
             signIn = (
                 <a className="mx_Auth_changeFlow" onClick={this.onLoginClick} href="#">
-                    { _t('I already have an account') }
+                    { _t('Sign in instead') }
                 </a>
             );
         }