Log Message:
finance/ledger2beancount: Update to 2.7.

Release ledger2beancount 2.7
* Fix parsing of amounts with decimal comma with default commodity in hledger mode
* Allow amounts without fractional part but decimal separator for hledger
* Improve pre-processing example in documentation
* Add support for amounts with plus sign
* Set option `name_income` for top-level account `Revenue`
* Fix whitespace handling for inline maths

Release ledger2beancount 2.6
* Round calculated total if needed for `price==cost` comparison
* Add `narration_tag` config variable to set narration from metadata
* Retain unconsummated payee/payer metadata
* Ensure UTF-8 output and assume UTF-8 input
* Document UTF-8 issue on Windows systems
* Add option to move posting-level tags to the transaction itself
* Add support for the `alias` sub-directive of `account` declarations
* Add support for the `payee` sub-directive of `account` declarations
* Support configuration file called `.ledger2beancount.yaml`
* Fix uninitialised value warning in hledger mode
* Print warning if account in assertion has sub-accounts
* Set commodity for commodity-less balance assertion
* Expand path name of `beancount_header` config variable
* Document handling of buckets
* Document pre- and post-processing examples
* Add `Dockerfile` to create Docker image