handle the stop codons, COSMIC errors download, ENSEMBL releases

[ypriverol]

• [x] handle the stop codons in ensembl databases
• [x] add new test for stop codons.
• [x] Cosmic error handling when the user can't log in.
• [x] Ensembl release issue #23
• [x] Add changelog.md to the project
• [x] Add code quality service.

[ypriverol]

@husensofteng do not merge yet the PR, still fixing COSMIC login error

[ypriverol]

@husensofteng the ensembl grch37 is implemented. Please Review the present PR.

[ypriverol]

@husensofteng the PR is now to be reviewed.