Move pymystem from hatbot repository
Some problems in build-assets
And some more in build-assets
Fix lang_utils' imports
Fix storages' getter and context management
Revert "Some problems in build-assets"

The problem was actually with context manager.
This reverts commit 996c3fae601b6a5348ade0004b663515cb73f20d.
Merge pull request #4 from hatbot-team/modifiers

Add some common modifiers
Merge pull request #7 from hatbot-team/synonyms-mergeable

Synonyms mergeable