file_formatter_spec: simplify tests a bit

* simplify test names

* use described_class instead of the actual name.
  It's shorter.

spec/commands/cat/file_formatter_spec.rb

@@ -12,68 +12,68 @@
     end
 
     describe "windows filesystem" do
-      it "should parse '/'style absolute path without line_num" do
+      it "parses '/'style absolute path without line_num" do
         file_with_embedded_line = "C:/Ruby193/pry_instance.rb"
-        ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+        ff = described_class.new(file_with_embedded_line, @p, @opt)
         file_name, line_num = ff.file_and_line
         file_name.should eq "C:/Ruby193/pry_instance.rb"
         line_num.should eq nil
       end
 
-      it "should parse '/'style absolute path with line_num" do
+      it "parses '/'style absolute path with line_num" do
         file_with_embedded_line = "C:/Ruby193/pry_instance.rb:2"
-        ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+        ff = described_class.new(file_with_embedded_line, @p, @opt)
         file_name, line_num = ff.file_and_line
         file_name.should eq "C:/Ruby193/pry_instance.rb"
         line_num.should eq 2
       end
 
-      it "should parse '\\'style absolute path without line_num" do
+      it "parses '\\'style absolute path without line_num" do
         file_with_embedded_line = "C:\\Ruby193\\pry_instance.rb"
-        ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+        ff = described_class.new(file_with_embedded_line, @p, @opt)
         file_name, line_num = ff.file_and_line
         file_name.should eq "C:\\Ruby193\\pry_instance.rb"
         line_num.should eq nil
       end
 
-      it "should parse '\\'style absolute path with line_num" do
+      it "parses '\\'style absolute path with line_num" do
         file_with_embedded_line = "C:\\Ruby193\\pry_instance.rb:2"
-        ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+        ff = described_class.new(file_with_embedded_line, @p, @opt)
         file_name, line_num = ff.file_and_line
         file_name.should eq "C:\\Ruby193\\pry_instance.rb"
         line_num.should eq 2
       end
     end
 
     describe "UNIX-like filesystem" do
-      it "should parse absolute path without line_num" do
+      it "parses absolute path without line_num" do
         file_with_embedded_line = "/Ruby193/pry_instance.rb"
-        ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+        ff = described_class.new(file_with_embedded_line, @p, @opt)
         file_name, line_num = ff.file_and_line
         file_name.should eq "/Ruby193/pry_instance.rb"
         line_num.should eq nil
       end
 
-      it "should parse absolute path with line_num" do
+      it "parses absolute path with line_num" do
         file_with_embedded_line = "/Ruby193/pry_instance.rb:2"
-        ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+        ff = described_class.new(file_with_embedded_line, @p, @opt)
         file_name, line_num = ff.file_and_line
         file_name.should eq "/Ruby193/pry_instance.rb"
         line_num.should eq 2
       end
     end
 
-    it "should parse relative path without line_num" do
+    it "parses relative path without line_num" do
       file_with_embedded_line = "pry_instance.rb"
-      ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+      ff = described_class.new(file_with_embedded_line, @p, @opt)
       file_name, line_num = ff.file_and_line
       file_name.should eq "pry_instance.rb"
       line_num.should eq nil
     end
 
-    it "should parse relative path with line_num" do
+    it "parses relative path with line_num" do
       file_with_embedded_line = "pry_instance.rb:2"
-      ff = Pry::Command::Cat::FileFormatter.new(file_with_embedded_line, @p, @opt)
+      ff = described_class.new(file_with_embedded_line, @p, @opt)
       file_name, line_num = ff.file_and_line
       file_name.should eq "pry_instance.rb"
       line_num.should eq 2
@@ -82,12 +82,12 @@
 
   describe "#format" do
     it "formats given files" do
-      ff = Pry::Command::Cat::FileFormatter.new(__FILE__, @p, @opt)
+      ff = described_class.new(__FILE__, @p, @opt)
       expect(ff.format).to match(/it "formats given files" do/)
     end
 
-    it "should format given files with line number" do
-      ff = Pry::Command::Cat::FileFormatter.new(__FILE__ + ':83', @p, @opt)
+    it "formats given files with line number" do
+      ff = described_class.new(__FILE__ + ':83', @p, @opt)
       expect(ff.format).to match(/it "formats given files" do/)
     end
   end