Added Error /Success messages in login and signup

[arpit456jain]

Related Issuse

I have added Error and Success Message in sign up and log in

Closes: #106

Describe the changes you've made

https://drive.google.com/file/d/1w6xr6ih9F4xQSMvCIMzI268txKLGvhgk/view?usp=sharing

Checklist:

• [x] My code follows the style guidelines of this project.
• [x] I have performed a self-review of my own code.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [ ] I have made corresponding changes to the documentation.
• [x] My changes generate no new warnings.

[arpit456jain]

@khannakshat7 kindly review my this PR and and my PR for feedback , it was ok from my side.

And may i format the login.html as it contains a lot of code its difficult to understand it. but if i format it it will show like whole file is changed that's why i asked before

[arpit456jain]

https://user-images.githubusercontent.com/55352601/116772053-0a8a7200-aa6b-11eb-97e0-de7a7f96296c.mp4

I forgot to show the password check here it is

[khannakshat7]

@arpit456jain I'll review it and merge

[arpit456jain]

@arpit456jain I'll review it and merge

ok @khannakshat7 and please review PR for Feedback

[arpit456jain]

@CodesbyUnnati @khannakshat7 please review 🙂

[khannakshat7]

@CodesbyUnnati @khannakshat7 please review 🙂

@arpit456jain I'll review it and merge soon

[khannakshat7]

@arpit456jain Good work buddy and sorry for the delay