Update Dependencies (#6)

* Update dependencies (some work done by Abe, some by me)
* Update to Rust 2021
* Update .gitignore to ignore macOS's .DS_Store file
* Make `--insecure` help message more scary
* Update to reqwest 0.11
* Remove now-unused URL crate dependency
* Update author
* Update version to v0.3.0

Co-authored-by: abe <arosloff@codedx.com>

Author: baffles

.gitignore

@@ -1,2 +1,3 @@
+.DS_Store
 target/
-.idea/
+.idea/