search Context classpath as well as System for migration dir

[scgilardi]

• the System classpath works a lot of the time, but didn't work for us in a docker container using tomcat: tomcat:9.0-jre8-alpine
• I think it would be reasonable to find these files the same way the Clojure compiler does all the time (using the Context ClassLoader which I believe internally searches the System ClassLoader as well, but ClassLoaders are a dark art), but this approach will ensure migratus works the same way after this patch in every deployment where it already works at all.

[yogthos]

Using the same approach as the Clojure compiler definitely makes sense, and thanks for making a PR with the fix. I just pushed out 1.0.6 to Clojars with the changes.

[scgilardi]

Thanks very much!

[yogthos]

👍