Fix Crystal build

[vladfaust]

It now successfully builds a file with Sublime builds feature (found at Tools -> Build).

Reference: https://www.sublimetext.com/docs/3/build_systems.html

Can't even find docs for "shell".

[vladfaust]

Working nicely! It only highlights the first output entry, which should be enough in most cases.

Unfortunately, crystal run does not print column numbers with text formatting. And json formatting doesn't work well with Sublime Builds when having multiple errors in the output (probably related to the lack of \n in the JSON output).

FYI, there are results of my experiments with the JSON output (should be escaped to use as a JSON value):

• "file_regex": ^\[{"file":"(?<filename>[\w\/]+.cr)","line":(?<line_number>\d+),"column":(?<column_number>\d+),"size":\d+,"message":"(?<message>[\w\s'#():]+)"}
• "line_regex": {"file":"(?:[\w\/]+.cr)","line":(?<line_number>\d+),"column":(?<column_number>\d+),"size":\d+,"message":"(?<message>[\w\s'#():]+)"}

[faustinoaq]

💯