Fixed Snowcrash version number requirement

[kielabokkie]

Blueman was throwing an exception on files created with the latest API Blueprint tools like Drafter because of the version number requirement. Removed this requirement and updated the code to support the AST format. Also updated the docs to make clear that Blueman only supports the AST format (which has been deprecated).

[codecov-io]

Current coverage is 94.07%

Merging #21 into master will decrease coverage by -0.12% as of 40be89a

@@            master     #21   diff @@
======================================
  Files            1       1       
  Stmts          155     135    -20
  Branches         0       0       
  Methods          8       8       
======================================
- Hit            146     127    -19
  Partial          0       0       
+ Missed           9       8     -1

Review entire Coverage Diff as of 40be89a

---

Uncovered Suggestions

1. +3.70% via ...d/ConvertCommand.php#87...91
2. +1.48% via ...d/ConvertCommand.php#142...143
3. +0.74% via ...d/ConvertCommand.php#251...251

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