build: drop support for go 1.14 (#11)

Signed-off-by: nscuro <nscuro@protonmail.com>

Closes #10

.github/workflows/ci.yml

@@ -26,7 +26,6 @@ jobs:
     strategy:
       matrix:
         go:
-          - "^1.14"
           - "^1.15"
           - "^1.16"
           - "^1.17"

README.md

@@ -29,7 +29,8 @@ Also, checkout the [`examples`](./example_test.go) to get an idea of how this li
 | cyclonedx-go versions | Supported Go versions | Supported CycloneDX spec |
 |:---------------------:|:---------------------:|:------------------------:|
 |    < v0.4.0           |         1.14+         |            1.2           |
-|   >= v0.4.0           |         1.14+         |            1.3           |
+|   == v0.4.0           |         1.14+         |            1.3           |
+|   >= v0.5.0           |         1.15+         |            1.3           |
 
 We're aiming to support all [officially supported](https://golang.org/doc/devel/release.html#policy) Go versions, plus
 an additional older version.

go.mod

@@ -1,6 +1,6 @@
 module github.com/CycloneDX/cyclonedx-go
 
-go 1.14
+go 1.15
 
 require (
 	github.com/bradleyjkemp/cupaloy/v2 v2.6.0