fix(#32): 🐛 only load config when needed and fixed relative path to support win 10

[Stormix]

This PR fixed the following bug:

---

Describe the bug
This relates to #32 . Running the init command fails since the cli expects a configuration when instantiated.

To Reproduce
Steps to reproduce the behavior:

1. install the library in a new project
2. run the init command

Expected behavior
After installing the library, a user should be able to initialize a new migrations folder/configuration.

---

It also fixed issues on Windows 10, where process.env.PWD is not defined (more info here) and uses path.join() to concatenate paths instead of raw string concatenation.

[Stormix]

@mycodeself

[mycodeself]

Hello, thank you for your PR and sorry for the delay.

Currently, we are running the cli creating a new instance of the CLI and executing it with ts-node as seen in the examples. I think this breaks this way of use, does it?

--

I have released a new version updating dependencies and adding your proposed changes using path.join()