add(gitea-api): issues and milestones getters

This implements the api getters for extracting the issues and milestones
for a given gitea repository. WIP for #1.

internal/gitea/gitea.go

@@ -0,0 +1,16 @@
+package gitea
+
+var API_PATH = "/api/v1"
+
+type Gitea struct {
+	base_url string
+}
+
+func NewGitea(base_url string) (gitea Gitea) {
+	gitea.base_url = base_url
+	return
+}
+
+func (gitea *Gitea) Url() string {
+	return gitea.base_url + API_PATH
+}