3.3.1 (#529)

* makefile wip

* feat: adds Makefile

Adds a `Makefile` for managing build-related tasks.

* chore: updates dependencies

* chore: updates dependencies

* chore: updates bin scripts

- Removes `build_release.sh`
- Places deprecation notice in `build_devel.sh`, as its purpose has been
  superceded by the `Makefile`.

* chore: updates bin scripts

- Removes `build_release.sh`
- Places deprecation notice in `build_devel.sh`, as its purpose has been
  superceded by the `Makefile`.

* fix: Makefile

Makes several corrections and improvements to the `Makefile`:

- Previously, the `ifeq` rules were not behaving as intended, due to
  false assumptions regarding how `make` fundamentally behaves.
  Malfunctioning imperative-style programming has been replaced with
  declarative rules to repair this issue.

- Previously, all release executables were zipped after compilation. In
  order to spare non-Windows users from (possibly) needing to install a
  package to unzip the executables, all non-Windows binaries are now
  compressed with `gzip`. (Windows executables are still compressed with
  `zip`.)

- Removes a bit of needlessly verbosity in several rules and paths.

* chore: updates dependencies

* chore: bumps version to 3.3.1

vendor/github.com/mattn/go-isatty/go.mod

@@ -2,4 +2,4 @@ module github.com/mattn/go-isatty
 
 go 1.12
 
-require golang.org/x/sys v0.0.0-20191026070338-33540a1f6037
+require golang.org/x/sys v0.0.0-20200116001909-b77594299b42