Merge pull request #99 from allegro/release/1.3.0

Release/1.3.0
Merge branch 'master' into hotfix/add-field-to-search-assets
change version
Merge pull request #100 from kula1922/hotfix/add-field-to-search-assets

Hotfix/add field to search assets
cores_count returns 0 instead of None
Remove back uppercase letter in CHANGES.rst
Merge pull request #101 from kula1922/hotfix/cores_count_returns_none

Hotfix/cores count returns none
Merge pull request #102 from allegro/master

Master
now sn in form have unlimited max_length
Name corrected
It was only bad field setting
If invoice number then invoice date is required
More clearly
remove needless code
add few docstrings
Default deprecation rate
Change test run command in travis file
fix run tests
Merge pull request #108 from kula1922/feature/add-travis-configuration

Change test run command in travis file
Merge pull request #104 from zefciu/decoupling

Decoupling