Updated Indian States and union territories as per iso:3166

[nishit01]

Updated Indian States and Union Territories as per iso 3166 (https://www.iso.org/obp/ui/#iso:code:3166:IN)

All Changes made in the code

1. Orissa replaced with Odisha
2. Pondicherry replaced with Puducherry
3. Updated Chattisgarh code (CG replaced with CT)
4. Moved Jammu and Kashmir from State to Union Territories
5. Added Ladakh in Union Territories
6. Modified Daman and Diu name with the updated iso code
7. Updated Andaman and Nicobar Union Territory Name

• Add an entry to the docs/changelog.rst describing the change.

• Add an entry for your name in the docs/authors.rst file if it's not
  already there.

[benkonrath]

@nishit01 This looks similar to #427. Can this one be closed?

[nishit01]

Hi @benkonrath, yes

[nishit01]

@benkonrath #426 failed Travis CI due to missing test cases, I added related testes to pass all checks in Travis CI. #427 contains code with the addition of related test cases