Log Message:
py-ruamel-yaml: updated to 0.15.54

[0, 15, 54]:
  - fix issue where a comment could pop-up twice in the output
  - fix issue where JSON object (mapping) without spaces was not parsed
    properly
  - fix issue where comments after empty flow-style mappings were not emitted

[0, 15, 53]:
  - fix issue with flow style mapping with comments gobbled newline
  - fix issue where single '+' under YAML 1.2 was interpreted as
    integer, erroring out

[0, 15, 52]:
  - added .copy() mapping representation for round-tripping
    (CommentedMap) to fix incomplete copies of merged mappings
  - Also unmade that class a subclass of ordereddict to solve incorrect behaviour
    for {**merged-mapping} and dict(**merged-mapping)

[0, 15, 51]:
  - Fix method name dumps (were not dotted) and loads (reported by Douglas Raillard
  - Fix spurious trailing white-space caused when the comment start
    column was no longer reached and there was no actual EOL comment
    (e.g. following empty line) and doing substitutions, or when
    quotes around scalars got dropped.

[0, 15, 50]:
  - Allow YAML() as a context manager for output, thereby making it much easier
    to generate multi-documents in a stream.
  - Fix issue with incorrect type information for load() and dump()