Fixed missing quotes around $BASH_IT variable

This should fix most issues where Bash-it is installed in a directory
containing spaces.

aliases/available/general.aliases.bash

@@ -21,7 +21,7 @@ alias _="sudo"
 # colored grep
 # Need to check an existing file for a pattern that will be found to ensure
 # that the check works when on an OS that supports the color option
-if grep --color=auto "a" $BASH_IT/*.md &> /dev/null
+if grep --color=auto "a" "${BASH_IT}/"*.md &> /dev/null
 then
   alias grep='grep --color=auto'
   export GREP_COLOR='1;33'