Stream output while shelling out to bash

When a command takes a long time we need visibility into what's happening. This change prints anything to stdout that is being executed by rundoc.

Close #30

CHANGELOG.md

@@ -1,6 +1,6 @@
 ## HEAD
 
-
+- Fix: Bash commands now stream their outputs while they're running (https://github.com/zombocom/rundoc/pull/57)
 - Change: Minimum selenium-webdriver is now 4.x. (https://github.com/zombocom/rundoc/pull/41)
 
 ## 2.0.1

lib/rundoc/code_command/bash.rb

@@ -40,8 +40,15 @@ def shell(cmd, stdin = nil)
     IO.popen(cmd, "w+") do |io|
       io << stdin if stdin
       io.close_write
-      result = sanitize_escape_chars io.read
+
+      until io.eof?
+        buffer = io.gets
+        puts "    #{buffer}"
+
+        result << sanitize_escape_chars(buffer)
+      end
     end
+
     unless $?.success?
       raise "Command `#{@line}` exited with non zero status: #{result}" unless keyword.to_s.include?("fail")
     end