Add solargraph LSP linter.

ale_linters/ruby/solargraph.vim

@@ -0,0 +1,19 @@
+" Author: Horacio Sanson - https://github.com/hsanson
+" Description: Solargraph Language Server https://solargraph.org/
+
+call ale#Set('ruby_solargraph_host', '127.0.0.1')
+call ale#Set('ruby_solargraph_port', '7658')
+
+function! ale_linters#ruby#solargraph#GetAddress(buffer) abort
+    let l:host = ale#Var(a:buffer, 'ruby_solargraph_host')
+    let l:port = ale#Var(a:buffer, 'ruby_solargraph_port')
+    return l:host . ':' . l:port
+endfunction
+
+call ale#linter#Define('ruby', {
+\   'name': 'solargraph',
+\   'lsp': 'socket',
+\   'address_callback': 'ale_linters#ruby#solargraph#GetAddress',
+\   'language': 'ruby',
+\   'project_root_callback': 'ale#ruby#FindProjectRoot'
+\})