Correct RELOAD_PATTERN
The entirety of the testenv-build function was previously defined in a make target but as it grew I found it easier to split out into its own script. In make, $ needs to be escaped as . However, as the functionality was separated into a script, this wasn't done and we kept the escaping as done in makefile, resulting in an incorrect regexp used here ( will evaluate to the current PID instead, thus the regexp won't match on the right thing).
Closes #171 (closed)