Use Ruby 2.7.2 (#15150)

thwait and e2mmap are no longer needed in Gemfile.
Gems properly require those.

.ruby-version

@@ -1 +1 @@
-2.6.6
+2.7.2

Dockerfile

@@ -40,7 +40,7 @@ RUN apt update && \
 	cd .. && rm -rf jemalloc-$JE_VER $JE_VER.tar.gz
 
 # Install Ruby
-ENV RUBY_VER="2.6.6"
+ENV RUBY_VER="2.7.2"
 ENV CPPFLAGS="-I/opt/jemalloc/include"
 ENV LDFLAGS="-L/opt/jemalloc/lib/"
 RUN apt update && \

Gemfile

@@ -11,9 +11,6 @@ gem 'sprockets', '~> 3.7.2'
 gem 'thor', '~> 1.0'
 gem 'rack', '~> 2.2.3'
 
-gem 'thwait', '~> 0.2.0'
-gem 'e2mmap', '~> 0.1.0'
-
 gem 'hamlit-rails', '~> 0.2'
 gem 'pg', '~> 1.2'
 gem 'makara', '~> 0.4'

Gemfile.lock

@@ -704,7 +704,6 @@ DEPENDENCIES
   discard (~> 1.2)
   doorkeeper (~> 5.4)
   dotenv-rails (~> 2.7)
-  e2mmap (~> 0.1.0)
   ed25519 (~> 1.2)
   fabrication (~> 2.21)
   faker (~> 2.14)
@@ -793,7 +792,6 @@ DEPENDENCIES
   streamio-ffmpeg (~> 3.0)
   strong_migrations (~> 0.7)
   thor (~> 1.0)
-  thwait (~> 0.2.0)
   tty-prompt (~> 0.22)
   twitter-text (~> 1.14)
   tzinfo-data (~> 1.2020)