Use https for github dependencies

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 * New command line interface to the compiler (`crystal build ...`, `crystal run ...`, `crystal spec`, etc.). The default is to compiler and run a program.
 * `crystal eval` without arguments reads from standard input.
+* Added preliminar `crystal deps` command.
 * `__FILE__`, `__DIR__` and `__LINE__`, when used as def default arguments, resolve to the caller location (similar to [D](http://dlang.org/traits.html#specialkeywords) and [Swift](https://developer.apple.com/swift/blog/?id=15))
 * Allow `as` to determine a type even if the casted value doesn't have a type yet.
 * Added `is_a?` in macros. The check is against an [AST node](https://github.com/manastech/crystal/blob/master/src/compiler/crystal/syntax/ast.cr) name. For example `node.is_a?(HashLiteral)`.

src/project/github_dependency.cr

@@ -11,7 +11,7 @@ class GitHubDependency < Dependency
 
   def install
     unless Dir.exists?(@target_dir)
-      `git clone git@github.com:#{@author}/#{@repository}.git #{@target_dir}`
+      `git clone https://github.com/#{@author}/#{@repository}.git #{@target_dir}`
     end
     `ln -sf ../#{@target_dir}/src libs/#{@repository}`