Fix dialyzer makefile commands

This PR requires the following workflow to run dialyzer on elixir:
Before first run (slow):
```
make build_plt
```
To run dialyze (relatively fast):
```
make dialyze
```
If OTP release is changed (slow):
```
make clean_plt built_plt
```
* Should we detect if plt missing when calling `dialyze` and if so build a plt?
* Should we include any of the additional warnings: `-Werror_handling -Wrace_conditions -Wunmatched_returns -Wunderspecs`? These can find bugs! But also may produce warnings everytime we want to ignore.
* Might want to add `--fullpath` I haven't actually run this PR yet (no time to build the plt until later)