upgrade to apline-3.15 and osm2pgsql 1.5.1

[cristianbogdan]

# Install the things we want to stick around
RUN apk add --no-cache \
        libgcc \
        libstdc++ \
        boost-filesystem \
        boost-system \
        boost-thread \
        expat \
        libbz2 \
        postgresql-libs \
        libpq \
        geos \
        proj \
        lua5.2 \
        lua5.2-libs

# Install develop tools and dependencies, build osm2pgsql and remove develop tools and dependencies
RUN apk add --no-cache --virtual .osm2pgsql-deps\
        make \
        cmake \
        expat-dev \
        g++ \
        git \
        boost-dev \
        zlib-dev \
        bzip2-dev \
        proj-dev \
        geos-dev \
        lua5.2-dev \
        postgresql-dev &&\
        cd $HOME &&\
        mkdir src &&\
        cd src &&\
        git clone --depth 1 --branch $OSM2PGSQL_VERSION https://github.com/openstreetmap/osm2pgsql.git &&\
        cd osm2pgsql &&\
        mkdir build &&\
        cd build &&\
        cmake -DLUA_LIBRARY=/usr/lib/liblua-5.2.so.0 .. &&\
        make &&\
        make install &&\
        cd $HOME &&\
        rm -rf src &&\
        apk --purge del .osm2pgsql-deps

Also I would suggest to include osmctools which are not available in Alpine but useful for osmconvert

RUN apk add --no-cache --virtual .osmctools-deps make g++ git autoconf automake libtool zlib-dev && \
  git clone --depth 1 https://gitlab.com/osm-c-tools/osmctools.git && \
  cd osmctools &&  autoreconf --install &&  ./configure &&  make install &&\
  rm -rf /osmctools &&\
  apk --purge del .osmctools-deps