dotenv-expand breaking build when "$" is used

Created by: jdcrensh

We use variables that include $ within the strings, which we don't want to be expanded. Escaping with \$ works fine when it occurs at the start of the string, but not anywhere else within the string.

Example:

REACT_APP_MYVAR=\$bar.baz <- works as expected, value is "$bar.baz" REACT_APP_MYVAR=foo\$bar.baz <- I'd expect "foo$bar.baz" but I get "foo\.baz"

I also tried working around the problem, like so:

BAR=\$bar
REACT_APP_MYVAR=foo$BAR.baz

But it gave the same result of "foo\.baz"