[BUG] BioFSharp.IO.Obo.parseOboTerms parsing error with ':'

[Freymaurer]

Describe the bug
I used the function mentioned in the issue header to parse obo files for SwateDB and noticed that i have some duplicate entries:

Example:

Now i checked into it and found out that most are created due to parsing errors as can be seen here:

If you check the accession numbers, e.g.:

http://purl.obolibrary.org/obo/MS_1001151
http://purl.obolibrary.org/obo/MS_1001261

the problem seems to involve ':' as part of the ontology term name.

To Reproduce
Steps to reproduce the behavior:

1. .fsx with biofsharp referenced.
2. use code snippet below to read in ms.obo.
3. search for shown accession values (id's).

codesnippet:

let msOntologyTerms = 
   __SOURCE_DIRECTORY__ + @"/../../ms.obo"
   |> Seq.fromFile
   |> parseOboTerms
   |> Array.ofSeq

Expected behavior
Should parse term name correctly or throw error.